Does the wax paper work well as a buffer between the fabric and the weight or will you see some sticking?
Wax paper works very well. Plastic painter's drop cloth material also works if you don't have a lot of excess glue escaping the joint.
On the side, what (besides snow) are you sleeping on in that lastish picture? -14 is freaking cold.
Well that photo wasn't from the -13F morning ... it was a relatively balmy +10F. But the setup was similar, from the bottom up:
* silnylon bivy bottom
* 3/8"x72"x20" generic blue foam pad
* a very old 72"x20" ridgerest pad
* Marmot Arroyo sleeping bag
* a Primaloft One quilt as a top bag (6oz/yd^2)
* momentum bivy top
Bivy zipped up to about shoulder level to allow me to breath outside.
The trip with the -13F morning I had two quilts over the bag, the second one with 3oz/yd^2 Climashield XP. Was warm in bed but getting up was a shock. Pack up while heating water (if your stove will light), do the chicken dance until the water is hot, eat the oatmeal and hot beverages, hit the trail and hope the wind doesn't kick up. That's my coldest morning to date, not sure I'd want to "improve" on that.