While I admire the ingenuity of the various ways to attach a quilt to a pad, as I mentioned, I do not use any of them, and here's why:
They are too complicated.
When sleeping, a complicated bed is the last thing I want. What I do want are super-easy ways to get warmer or cooler when needed. If too warm, uncover portions of sleeping self, if too cool, cover up sleeping self. Do these while unconscious.
A commodious bivvy helps keep the operation together, and also reduces the effect of wind and the dreaded drafts. It's a ground cloth. It's insect protection. It defeats wind-blown spray (I hope!). I made it at home out of that soft, quiet version of Tyvek for a few bucks. No stitches, just seam tape. One piece. Tools: Straight-edge, Tape Measure, Sharpie, Scissors. Easy.