Stuck on "Connecting to Server"

So, went to sleep with the game running fine, woke up to it giving a server connection error. It happens sometimes, so I restart the game client and now it's stuck on connecting to server.

I've done a full restart of my computer, restarted steam (again), validated game files (had 100 odd files redownloaded), reinstalled the game, many game restart attempts, another game validation (1 file). Still stuck at connecting to server or validating game definitions.

Wondering if this is just me, or if there's anything else I should try.