Those particular bolts are held in with Locktite which makes their removal a real bear. Applying some serious heat to the bolt head to loosen the Locktite's grip is some good magic to try.
If you do strip the bolt heads out, I would drill the heads (just the head) off which will leave enough of the threaded stud behind that you should be able to unscrew it with a set of vise grips set to "extra tight".
However, if you drill the heads off, you will need to get all of the bolts out so the hinge can be removed to give sufficient access to the remaining threaded stud. Make sure to stop drilling once the bolt head comes off in order to leave enough of the stud behind. Use a drill bit just slightly larger than the diameter of the threaded portion but still small enough to fit through the bolt hole in the hinge.