Prepping the post-Brexit apocalypse bunker with a "dig for victory" poster and a newspaper cutout of Theresa May on the wall for darts practice during electrical blackouts we also have the Freedombone mesh. The mesh system is a bootable USB version of Debian which can be used with laptops, and there's also an image which can be used with the Beaglebone Black to increase wifi network coverage. Even if the internet is unavailable the mesh network can carry on providing a local communications system.
Recently I've improved the internet functionality so that if you plug a mesh system into your internet router with an ethernet cable then it just automatically becomes a gateway for any other peers in the network. This avoids needing to do any manual network restarts and so makes things more convenient.
I've also removed the Patchwork SSB client because it was difficult to maintain the installation of that on a 32bit version of Debian. I'm still using 32bit images for the mesh, because if you're up against it then any old hardware could be requisitioned at short notice to build a mesh and there may still be old 32bit laptops stashed at the back of closets.