wouldn't the bandwidth requirements for a home VPN connection to 6 separate VM be just a touch inadequate?
Probably not, there's no way he's physically interacting with 6 machines simultaneously. It's not humanely possible
Any traffic between VMs would be kept within his home network, VPN would merely be for RDP or similar access.
Granted it's not going to be 32bit graphics, but it should be sufficient.
I'm not sure how a school can rely on student's to bring their own hardware in order to do the lab work. That doesn't seem right. Why attend class at all then? Might as well just do the work from home. And if for some strange reason that's how the school works, then they should have a contract with a company to provide the students with adequate laptops at a discounted price.