Bld. B/Room B is on the school network. In this room is a 'private' network with a RouterB that is connected to one port on that network. The devices on the private network cannot/should not be run on the larger network.
Bld. A/Room A is also on the school network, and is on the same VLan as Room B, above. We need to connect some RoomA computers to the private network in RoomB. How best to do so? They are about 500 ft apart.
One possibility is to use a partitioned hard drive, boot into its 'RoomB' setup, that uses a wireless adapter, and connects to an in-room router. That router, RouterA, needs to connect via VPN to RouterB.
If this is a good plan, how to connect the two routers over the common VLan they are both connected to?