Loving his thread and the wisdom from you folks with experience!
I'll make one assertion that is perhaps a sort of complication …
Here in the frozen North (southern Ontario, which has actually been uncharacteristically warm this season) I used to teach about snow ecology. We'd dig a pit through snow down to ground level, clean the face to a vertical plane so as to feel the different crystalline layers, and then insert long thermometers into each separate layer. For deep snow (knee-deep and more), the ground level is almost always at or even above freezing. The temperature grades to cooler as we approached the surface. Snow is a good insulator (and there's a whole living ecosystem under a good snowpack).
However, this gets somewhat complicated when we then consider sleeping on the ground as compared to sleeping on a layer of compressed snow. Depending on the extent of the snow compression, and on the resultant crystal structure of the snow, and the extent of heat ’leaking’ through your bottom pad layer, the thermal insulation value of the compressed snow as compared to the thermal insulation value of the near-frozen ground will vary.
TLDR: I would prefer dryish cold ground to all but the least-compressed fluffy dry snow. The wetter the ground, the more I'd go with lightly-compressed snow.
Bruce Traillium