Framework 12 is well aligned with this use case. Hackable, durable/utilitarian design, lower priced, aimed for youth and education markets (has a bit of the EeePC spirit). Well, those were the initial design goals of the concept, but then they sort of made a more general purpose laptop that everyone at the company fell in love with, which led to it actually going to production.

12" is on the smaller side, but it's also a 2in1 that can be used in a desk setup as an extra monitor. I'd ship them a cheap lightning portable monitor, simple keyboard+mouse pack, and for $100 more they have a durable portable laptop and a simple two monitor desk setup for dev.