As others have said, there are no 6,500 yard courses out there that rate up much higher than 72.
My home course is about 6,450 and the longest par 4 is 423 yards. The longest par 5 is 540 yards. In theory, both would be reachable in regulation for a guy who hits it 225 yards off the tee. Of course, being that short puts a lot of stress on the rest of your game, but in theory I suppose that it's possible.