That is cold, we usually get some of that in February, freeze the nose hair in a few seconds. Back in my late 20s I got a new HD down sleeping bag that was good for -40 so I tried it out new years eve on the pourch ,and the temperature was -34 that night. I did sleep but it was a very lite sleep and if I moved the cold air came in the small hole I was breathing thru. Never tried it again that cold. Young and dumb