> Or, if you're on this site, it's a great excuse to sit in a small room with a view and not talk to anyone for several days, just read, write and program.
This sounds like fun. I wonder if there are any European routes that are as long/uninterrupted that I could try that on.
Not really - the only trains taking longer than 24 hours in Europe are the sleepers to Moscow, and the longest of those (Nice-Moscow) only takes 48 hours. There are then much longer trains from Moscow into Asia though, up to the famous Trans-Siberian (6 days).
I went London-Japan overland but my longest single segment was two and a half days (Moscow-Shymkent), and that was about right - time to relax and do nothing for a bit, but by the third morning I had definitely spent enough time in the same compartment, as nice as it was.
Not really within the EU - we have reasonably fast rail that prioritises passenger travel over freight - but e.g. Moscow to Beijing takes 6 or 7 nights, and you could get to Moscow itself by sleeper train if you're up for it.
This sounds like fun. I wonder if there are any European routes that are as long/uninterrupted that I could try that on.