I did the first two legs of the Laurel Highlands Trail a month or so ago: Ohiopyle -> Ohiopyle Shelters -> Rte 653. It requires being dropped or a car-shuffle, and while not huge distances, the elevation makes it a challenging but rewarding two days (to be fair the first day was short). We chose to camp at 653 on the second night, but you could also just walk out. I hear 653 -> Grindel is very pretty too, and am going back to do that in a few weeks.
Two potential bonuses depending on your needs: you can reserve a shelter instead of a campsite for peace of mind in foul weather. Also saves carrying tents. There are pumps are the sites (still need to treat the water) but saves a lot of weight. There is free firewood at each stop.
While this sounds "camp site-y" there is a limit on the occupancy (not nearly filled when we were there), and the sites are walk in only, so it doesn't feel like a KOA.
But if you are looking for true backcountry, I'll follow this post with interest!
