You’re right about cheap laptops, but there are still (AFAICT) plenty or WiFi-only chromebooks, which is the big thing in education. Also tablets, kindles, nintendos...

I agree with the suggestion that using the cellular network is the way to go, I just think that turning that cellular data into WiFi will allow more devices to connect, and more freedom in how people choose to use their connection. So I would suggest portable cellular-to-WiFi routers rather than building the cellular connection into a laptop.