Hopefully not too much of a hijack of this thread, as some earlier comments related ---
I just did a 3-day snowshoe trip where I slept under a tarp on snow/ice. I.e., packed down slick snow, virtually ice, I guess, temperature right around freezing.
My polycro groundcloth was useless, as even on very level ground it was sliding around a lot, quite frictionless. I had two 1/8" GG ccf pads to combine with my inflatable, so fortunately was able to put one of those under the inflatable to keep it from sliding.
I'm speculating that I should be using tyvek as a groundcloth when tarp camping on snow in future? Most winter camping I've done in the past has been with a floored tent, so this was a new one on me.