For a one-time $60/computer they could put a 1 TB nvme drive in preloaded with whatever software they need, all of English wikipedia, all classic literature and textbooks they will reference, and 850 GB of whatever else is useful reference material (e.g. maybe all of the Khan Academy videos). It's very non-obvious to me that school computers need an Internet connection at all. Have it back up the kids' home folders onto a school network drive automatically when it gets on the school wifi.