Mine's a 4th gen X1 carbon with an ancient Antergos install from 2016 that I converted to normal arch after they closed the project. i3wm, probably some thinkpad specific tweaks from the arch wiki but the machine is so damn stable I rarely think about it.
Definitely not physically possible in my bag. I've chalked it up to the fact that linux desktop environments are just a total hodgepodge of weird components with unclear responsibility boundaries that couldn't possibly handle all the edge cases properly when you stick them all together. This leads to stuff like the fact that if I suspend my laptop with an external monitor connected, but then un-suspend it without that external monitor connected, I'm often presented with a lock screen that I can't actually interact with, forcing me to either seek out a monitor or switch over to text console to log in and kill my session.