Sure there is..A VPN....Soon enough MLB will catch up with that.
When I had MLB.tv I was using a zip that is a legitimate zip code but was not in MLB's data base. It was a new zip code that was added when the USPS built a new PO in town here.
Toward the end of the season, I received a message from MLB that their system did not or could not verify the zip code. So I had to use my "real" one....
VPN's are not fool proof.
For example, I have a friend who lives in a state where betting horse racing on line into a US based wagering site( ADW). In order to keep the account he used a VPN...A period of time went by and the Site's system flagged his account. The ADW could not identify the location of the computer he was using. Once that occurs, the ADW system "assumes" the user is betting from an unauthorized location. Shut down.