I'd forgotten all about the ESP8266 but this project is about 95% of what I'm aiming for. The rest should be relatively trivial programming work, so thanks!

Can't speak for the other guy (who wants a portable monitor+keyboard system), but what I'm mostly looking for is a terminal that I could carry around/outside the house (i.e. potentially high-glare conditions) and program while connected to wifi, while not recharging for as long as possible, so this is perfect.

Maybe I can embed some stuff like vim or emacs on the device itself to help reduce utilization of the wifi. Is there any sort of "smart" protocol that could handle buffering files while editing on a remote host? I can probably do it, but I'd rather not reinvent the wheel, caching can be non-trivial.

Secondary use-case: RTTY or PSK31 or other amateur-radio textmode terminal, that could idle for as long as possible on a portable (QRP) battery pack. When you're schlepping the gear around, every ounce counts. Something that can talk serial is probably good enough, wifi is redundant there.

Regarding your query about a remote login protocol that's smart about buffering, etc, I think you're looking for mosh: https://mosh.mit.edu/

I have been working on the MagicShifter project (http://magicshifter.net/) and we designed the board so that the UART is available (for MIDI and other things).

If I can find a paper-ink display that I can drive somehow with a UART, I'd be quite happy to wire it up and hack up a MagicShifter app that turns it into a dumb terminal. Know of such a thing?

I regularly use Vim over high latency connections (50ms+) for extended periods, and it's really not that big a deal.

Wait, over 50ms is high latency now? That's less than transatlantic traffic delays, for example. I think you have to be in the actually noticeable (say 250ms plus) range to count as high.

Not to sounds like a Monty Python skit, but 50ms really does seem like luxury to me :-). I guess to back up the OP's point, I regularly use vim over 250ms+ latency lines for hours on end. It's not fantastic, but it's definitely doable. You need to have your vim golf game up to par, though :-)

You know your latency is high when your mental model switches from vi(1) to ed(1).

If you use classic vi modes, I think vi/vim is much more forgiving over high latency than emacs, for some reason.