I'm not sure I have a quick answer to your question - others might.
If I were in your shoes, I'd be measuring out the distances on the potential setup and mimicking the geometry with 2x4's on the driveway (ie - run a 2x4 long enough to mimic the distance from the rear wheel to the hitch, at the height of the bottom of your loaded hitch and see what it does at the point of concern, then repeat from the trailer side).
My only other comment would be to remind you that the pivot point between your truck and trailer isn't your only concern - you need to worry about the tail hitting the backside of the hill as well.
