While it's common for tournament X-Wing to see all ships destroyed in a match - this isn't required . The Ghost and all Rebel fighters have hyperdrives - they could just leave the battlefield. Indeed, presumably, that's what "going off the map edge" represents - for purpose of a making a viable game balance out of it, you'd probably need instructions that the Rebels can only disengage off one side of the map (else are considered 'captured'), while the Imperial forces can only disengage off the other side of the map (to return to their ship) in games where their ship isn't already present (we've got the Gozanti, after all).
It's doable!
It would be really interesting to see MOV reflected in the amount of points you can safely salvage by hypering out, rather than just surviving. The rules for hypering would need to be written with great care, of course.