Brilliant concept! I recently met the fine folks at Beekee who make something rather similar: https://beekee.ch/beekeebox/

It's an apparently simple problem on the surface, but quite hard to get it right... I once worked on a wireless network deployment for a transit refugee camp, and at least that was built on the assumption that some sort of Internet connection would be available at all times, making remote management possible. And even then it was tough to manage considering all other constraints.

I can only imagine how hard it is to deliver this kind of service reliably when Internet is rarely if ever available.