The problem I have with the zero 2w is that building anything on it seems to knock out the wifi. I've got a couple on the local network as terminals and if I try to build (e.g.) a recent python interpreter, the ssh connection dies to the extent that I have to power-cycle them. I presume they're just going into swap, but they never come back. Now that's not your use-case if you've got a remote server and all you're using them for is a thin client, but they aren't exactly usable as general purpose devices.

I do like the sound of that setup, though. Portable monitor plus powerbank is neat, and I can't help wondering if that plus a wireguard network wouldn't be the right way to do things away from home. There are more efficient SBCs but if the screen is the big drain that's exactly the choice I'd make too.