It will get better because you are going through the trial and error needed to make it so. Much easier to sort out in the backyard though.
1-A better fitting UQ. Maybe a bit more tweaking on your DIY rig to make it work? Even though pads are of the Devil (IMO) bring one with the UQ just for extra insulation.
2-Hang your tarp lower to put a better barrier between you and the breeze. Maybe even a square set up tarp for more coverage.
Mark is the name and If there is more than one way to understand what I just said....I meant the good one.
Earth First! We'll dirt bike ride the other planets later.