well after saying that I think you are nuts (Ive commuted at those temps, but riding all day and sleeping....yowzer), my one suggestion is how a candle lantern can easily and safely strung inside a tent. Ive done so for decades. I have some string rigged up in the upper center of my tent, and my candle lantern is hooked onto the thin rope using a bit of coiled metal wire that I keep in the plastic bag with my lantern, extra candles and matches. Works great for taking the damp chill out of a tent, but would help a bit for warmth also, although that would depend on how much wind there is, and how much meshing is on tent.
ski googles, I cant believe you didnt take them.
I know folks winter camp, so its certainly doable, you just have to address the factors that need addressing, so if this is what turns your crank, go for it, with the adjusting of stuff, and it will become realistic and more comfortable.
good luck on skin on nose, you certainly dont want to screw around with frostbite. Ive never had anything to that level, so hope it just peels like sunburn and comes back properly.