diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1540092ab67..9d1eb7be0ba 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -97,26 +97,33 @@ jobs:
     # Test network packages
 
     - name: ntp-client [test]
-      run: cabal run ntp-client:test
+      run: cabal run ntp-client:test -- +RTS -maxN2 -RTS
+
+    - name: monoidal-synchronisation [test]
+      run: cabal run monoidal-synchronisation:test -- +RTS -maxN2 -RTS
 
     - name: network-mux [test]
+      # TODO: issue #4635 to enable `+RTS -N`
       run: cabal run network-mux:test
 
     - name: ourobors-network-testing [test]
-      run: cabal run ouroboros-network-testing:test
+      run: cabal run ouroboros-network-testing:test -- +RTS -maxN2 -RTS
 
     - name: ourobors-network-framework [test]
+      # TODO: enable `+RTS -N`
       run: cabal run ouroboros-network-framework:test
 
+    # TODO: run CDDL
+
     - name: ouroboros-network-protocols [test]
-      run: cabal run ouroboros-network-protocols:test
+      run: cabal run ouroboros-network-protocols:test -- +RTS -maxN2 -RTS
 
     # We don't run cddl in GitHub actions (only on Hydra).
     # - name: ouroboros-network-protocols [cddl]
     #   run: cabal run ouroboros-network-protocols-test:cddl
 
     - name: ouroboros-network [test]
-      run: cabal run ouroboros-network:test
+      run: cabal run ouroboros-network:test -- +RTS -maxN2 -RTS
 
     # Uncomment the following back in for debugging. Remember to launch a `pwsh` from
     # the tmux session to debug `pwsh` issues. And be reminded that the `/msys2` and
diff --git a/.github/workflows/checks.yml b/.github/workflows/checks.yml
index 0e9ecca448d..220540f1c79 100644
--- a/.github/workflows/checks.yml
+++ b/.github/workflows/checks.yml
@@ -11,7 +11,6 @@ on:
 jobs:
   check-git-dependencies:
     name: Check git dependencies
-    if: ${{ github.event_name == 'push' || !github.event.pull_request.draft }}
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -24,7 +23,6 @@ jobs:
 
   check-changelogs:
     name: Check changelogs
-    if: ${{ github.event_name == 'push' || !github.event.pull_request.draft }}
     runs-on: ubuntu-latest
     defaults:
       run:
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
new file mode 100644
index 00000000000..3f1c71182a7
--- /dev/null
+++ b/.github/workflows/nightly.yml
@@ -0,0 +1,160 @@
+name: Nightly Haskell CI
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+on:
+  schedule:
+    - cron: 0 3 * * *
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        ghc: ["8.10.7", "9.6.2"]
+        os: [ubuntu-latest]
+
+    env:
+      # Modify this value to "invalidate" all cabal caches.
+      CABAL_CACHE_VERSION: "2022-12-30"
+      # Modify this value to "invalidate" the cabal store cache only.
+      CACHE_VERSION: "20220919"
+      # Modify this value to "invalidate" the dist-newstyle cache only.
+      DIST_CACHE_VERSION: "20221122"
+
+    steps:
+
+    - name: Install Haskell
+      uses: input-output-hk/setup-haskell@v1
+      id: setup-haskell
+      with:
+        ghc-version: ${{ matrix.ghc }}
+        cabal-version: "3.10.1.0"
+        pacman-packages: >
+          mingw-w64-x86_64-pkg-config
+          mingw-w64-x86_64-openssl
+          mingw-w64-x86_64-sed
+          base-devel
+          autoconf-wrapper
+          autoconf
+          automake
+          libtool
+          make
+
+    - name: Set up Ruby
+      if: runner.os == 'Linux'
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 2.7
+
+    - name: Install cddl
+      if: runner.os == 'Linux'
+      run: |
+        gem install cddl -v 0.8.27
+
+    - uses: actions/checkout@v3
+
+    - name: "Configure cabal.project.local"
+      run: |
+        cp ./scripts/ci/cabal.project.nightly${{ runner.os }} cabal.project.local
+
+    - name: Update PATH (Windows)
+      if: runner.os == 'Windows'
+      run: |
+        $env:PATH=("C:\msys64\mingw64\bin;{0}" -f $env:PATH)
+        echo "PATH=$env:PATH" >> $env:GITHUB_ENV
+
+    - name: Update PATH (Linux)
+      if: runner.os == 'Linux'
+      run:
+        echo "$HOME/.local/bin" >> $GITHUB_PATH
+
+    - name: Update Hackage and CHaP
+      run: cabal update
+
+    - name: Record dependencies
+      id: record-deps
+      run: |
+        cabal build all --dry-run
+        cat dist-newstyle/cache/plan.json | jq -L .github/workflows/jq-install-plan | sort | uniq > dependencies.txt
+
+    - uses: actions/cache/restore@v3
+      name: "Restore cache: `cabal store`"
+      id: restore-cabal-store
+      with:
+        path: ${{ steps.setup-haskell.outputs.cabal-store }}
+        key: cache-dependencies-${{ env.CABAL_CACHE_VERSION }}-${{ env.CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('dependencies.txt') }}
+        restore-keys: cache-dependencies-${{ env.CABAL_CACHE_VERSION }}-${{ env.CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}
+
+    - uses: actions/cache@v3
+      name: "Cache `dist-newstyle`"
+      with:
+        path: |
+          dist-newstyle
+          !dist-newstyle/**/.git
+        key: cache-dist-${{ env.CABAL_CACHE_VERSION }}-${{ env.DIST_CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('cabal.project') }}
+        restore-keys: cache-dist-${{ env.CABAL_CACHE_VERSION }}-${{ env.DIST_CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}
+
+    - name: Build dependencies
+      run: cabal build --only-dependencies all -j
+
+    - uses: actions/cache/save@v3
+      name: "Save cache: `cabal store`"
+      with:
+        path: ${{ steps.setup-haskell.outputs.cabal-store }}
+        key: cache-dependencies-${{ env.CABAL_CACHE_VERSION }}-${{ env.CACHE_VERSION }}-${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('dependencies.txt') }}
+
+    - name: Build projects [build]
+      run: cabal build all -j
+
+    # Test network packages
+
+    - name: ntp-client [test]
+      run: cabal run ntp-client:test -- +RTS -maxN2 -RTS
+
+    - name: monoidal-synchronisation [test]
+      run: cabal run monoidal-synchronisation:test -- +RTS -maxN2 -RTS
+
+    - name: network-mux [test]
+      # TODO: issue #4635 to enable `+RTS -N`
+      run: cabal run network-mux:test
+
+    - name: ourobors-network-testing [test]
+      run: cabal run ouroboros-network-testing:test -- +RTS -maxN2 -RTS
+
+    - name: ourobors-network-framework [test]
+      # TODO: enable `+RTS -N`
+      run: cabal run ouroboros-network-framework:test
+
+    - name: ouroboros-network-protocols [test]
+      run: cabal run ouroboros-network-protocols:test -- +RTS -maxN2 -RTS
+
+    - name: ouroboros-netowrk-protocols [cddl]
+      if: runner.os == 'Linux'
+      run: cabal run ouroboros-network-protocols:cddl -- +RTS -maxN2 -RTS
+
+    - name: ouroboros-network [test]
+      run: cabal run ouroboros-network:test -- +RTS -maxN2 -RTS
+
+    # Uncomment the following back in for debugging. Remember to launch a `pwsh` from
+    # the tmux session to debug `pwsh` issues. And be reminded that the `/msys2` and
+    # `/msys2/mingw64` paths are not in PATH by default for the workflow, but tmate
+    # will put them in.
+    # You may also want to run
+    #
+    #   $env:PATH=("C:\Program Files\PowerShell\7;{0}" -f $env:ORIGINAL_PATH)
+    #
+    # to restore the original path.  Do note that some test might need msys2
+    # and will silently fail if msys2 is not in path. See the "Run tests" step.
+    #
+    # - name: Set up tmate session
+    #   if: ${{ failure() }}
+    #   uses: mxschmitt/action-tmate@v3
+    #   with:
+    #     limit-access-to-actor: true
+
diff --git a/README.md b/README.md
index fa03b94329a..911b7962151 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 # [Ouroboros-Network][ouroboros-network]
 
 [![Haskell CI](https://img.shields.io/github/actions/workflow/status/input-output-hk/ouroboros-network/build.yml?branch=master&label=Build&style=for-the-badge)](https://github.com/input-output-hk/ouroboros-network/actions/workflows/build.yml)
+[![Nightly CI](https://img.shields.io/github/actions/workflow/status/input-output-hk/ouroboros-network/nightly.yml?branch=master&label=Nightly&style=for-the-badge)](https://github.com/input-output-hk/ouroboros-network/actions/workflows/nightly.yml)
 [![Haddocks](https://img.shields.io/github/actions/workflow/status/input-output-hk/ouroboros-network/github-page.yml?branch=master&label=Haddocks&style=for-the-badge)](https://github.com/input-output-hk/ouroboros-network/actions/workflows/github-page.yml)
 [![handbook](https://img.shields.io/badge/policy-Cardano%20Engineering%20Handbook-informational?style=for-the-badge)](https://input-output-hk.github.io/cardano-engineering-handbook)
 
diff --git a/ntp-client/ntp-client.cabal b/ntp-client/ntp-client.cabal
index 94eaccad890..03898fbabcf 100644
--- a/ntp-client/ntp-client.cabal
+++ b/ntp-client/ntp-client.cabal
@@ -59,6 +59,7 @@ test-suite test
   default-language:   Haskell2010
   ghc-options:        -Wall
                       -Wunused-packages
+                      -threaded
 
 executable demo-ntp-client
   hs-source-dirs:     demo
diff --git a/ouroboros-network-protocols/ouroboros-network-protocols.cabal b/ouroboros-network-protocols/ouroboros-network-protocols.cabal
index 177361d8e68..53a1095072b 100644
--- a/ouroboros-network-protocols/ouroboros-network-protocols.cabal
+++ b/ouroboros-network-protocols/ouroboros-network-protocols.cabal
@@ -205,7 +205,8 @@ test-suite test
                        ouroboros-network-protocols:testlib,
                        ouroboros-network-testing ^>= 0.3
 
-  ghc-options:         -Wall
+  ghc-options:         -threaded
+                       -Wall
                        -Wunused-packages
 
 test-suite cddl
@@ -243,7 +244,8 @@ test-suite cddl
                        ouroboros-network-protocols,
                        ouroboros-network-protocols:testlib
 
-  ghc-options:         -Wall
+  ghc-options:         -threaded
+                       -Wall
                        -Wno-unticked-promoted-constructors
                        -Wcompat
                        -Wunused-packages
diff --git a/ouroboros-network/test/Test/Ouroboros/Network/PeerSelection.hs b/ouroboros-network/test/Test/Ouroboros/Network/PeerSelection.hs
index 32ec98f801a..1ede66baaf6 100644
--- a/ouroboros-network/test/Test/Ouroboros/Network/PeerSelection.hs
+++ b/ouroboros-network/test/Test/Ouroboros/Network/PeerSelection.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE BangPatterns               #-}
-{-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DeriveFunctor              #-}
 {-# LANGUAGE DerivingStrategies         #-}
 {-# LANGUAGE DerivingVia                #-}
@@ -175,10 +174,7 @@ tests =
 
   , testGroup "races"
     [ nightlyTest $ testProperty "governor no livelock"       $ prop_explore_governor_nolivelock
--- `IOSimPOR` is consumes too much RAM on Windows
-#if !defined(mingw32_HOST_OS)
-    ,               testProperty "governor connection status" $ prop_explore_governor_connstatus
-#endif
+    , nightlyTest $ testProperty "governor connection status" $ prop_explore_governor_connstatus
     ]
   ]
   --TODO: We should add separate properties to check that we do not overshoot
diff --git a/scripts/ci/cabal.project.local.Linux b/scripts/ci/cabal.project.local.Linux
index d1116c4c92a..66d3cb40b28 100644
--- a/scripts/ci/cabal.project.local.Linux
+++ b/scripts/ci/cabal.project.local.Linux
@@ -27,8 +27,9 @@ package ouroboros-network-mock
 package ouroboros-network-testing
   ghc-options: -fno-ignore-asserts -Werror
 
+-- IPv6 tests are DISABLED
 package ouroboros-network-framework
-  flags: +ipv6
+  flags: -ipv6
   ghc-options: -fno-ignore-asserts -Werror
 
 package ouroboros-network-protocols
diff --git a/scripts/ci/cabal.project.nightly.Linux b/scripts/ci/cabal.project.nightly.Linux
new file mode 100644
index 00000000000..386b7639a1a
--- /dev/null
+++ b/scripts/ci/cabal.project.nightly.Linux
@@ -0,0 +1,44 @@
+max-backjumps: 5000
+reorder-goals: True
+tests: True
+benchmarks: True
+
+package strict-checked-vars
+  flags: +checktvarinvariants +checkmvarinvariants
+
+package ntp-client
+  flags: +demo
+
+package network-mux
+  flags: +ipv6
+  ghc-options: -fno-ignore-asserts -Werror
+
+package ouroboros-network-api
+  flags: +asserts
+  ghc-options: -fno-ignore-asserts -Werror
+
+package ouroboros-network-mock
+  ghc-options: -fno-ignore-asserts -Werror
+
+package ouroboros-network-testing
+  flags: +nightly
+  ghc-options: -fno-ignore-asserts -Werror
+
+-- IPv6 tests are DISABLED
+package ouroboros-network-framework
+  flags: -ipv6
+  ghc-options: -fno-ignore-asserts -Werror
+
+package ouroboros-network-protocols
+  flags: +cddl
+  ghc-options: -fno-ignore-asserts -Werror
+
+package ouroboros-network
+  ghc-options: -fno-ignore-asserts -Werror
+
+package cardano-ping
+  ghc-options: -fno-ignore-asserts -Werror
+
+package cardano-client
+  ghc-options: -fno-ignore-asserts -Werror
+