This seems like it's going to end up being the only practical option:

https://pine64.org/devices/pinephone/

Might not be great, but at least they work. :)

Yes, a dumbphone. If I can actually find one, anyway. I am very skeptical that I can (the "dumbphones" I've found so far are all smartphones with very limited capabilities), so I'll go with the least capable phone I can locate.