I was under the impression that a VPN connection would be encrypted, and since I’d be still making accounts that would have to be signed into in order to access the data, someone attempting to steal the data would have to have the credentials to do so. RDP access (meaning full system control) would not be set up outside the local network, and remote access would be done through Windows Server VPN.

As stated above, I don’t really have that option. I don’t own the home, and the homeowner isn’t willing to bend on switching off the ISP-Provided router, and modern spectrum routers can’t be configured to bridged/access point mode.

Local to the network. So I’d be a local RDP connection, meaning no need for port-forwarding on the router (yet).