Excellent post Cannibal. .
Being from Northern Ontario, we get our fair share of cold. I've never had any desire to winter camp or winter hang. I love being outdoors in the winter to play, but would never consider sleeping out there. For those that do, your advice is sound. Frostbite and hypothermia are not to be toyed with, they are both very dangerous conditions that need immediate treatment.
Your comment that 'the cold makes you funny' (I call it crazycold) is similar to 'nirvana of the deep' where divers start making irrational decisions while underwater. If you're alone, there's no one to tell you that you're experiencing it, and your decisions can very well cost you your life.
For those that do want to experiment with the winter hang, don't go alone and as Cannibal already pointed out, always have a backup plan in case things go wrong...which they can...especially in the cold.