Pi5 may be a good solution then. Might also try a radxa x4. It has wifi 6 so more bandwidth for multiple wifi clients. Plus an m.2 slot. Only thing that sucks is there’s like no cases for it.

Yeah you can use the rpi as the router too

Probably an rpi and a travel router. But seems like the best setup would be a media server you kept at home and a VPN to connect to it from anywhere.

Might also try your local library and see if they give you free access to hoopla and kanopy!