We haven't even really seen much at all of the current campaign world. A mountain pass trade route could probably be incorporated into your campaign world Randallw without much effort. Just forget about the names of cities mentioned previously and replace them with cities in your world. Don't even need the teleporting.
The problem is not so much switching worlds, as it is switching worlds a lot, as you mentioned... Might as well play Planescape or Spelljammer if that is going to happen.
