My knowledge is pretty dated, Brett, so take it with a grain of salt. A lot has probably changed.
For VFR flight plans, you are not bound to follow it. You can file and then do what you want. When you arrive, or at some time not too long after you were supposed to arrive, you must close your VFR flight plan. In my day that was usually done by telephone to the Flight Service Station but could be done by radio if you were somewhere they had a frequency listed. If you failed to do that, it would (slowly) move toward a search and rescue by Civil Air Patrol, but they did a lot of things