While I am leery of the stability of the post-avalanche snow, I will assume the current state is safe for a snow cave now that the disaster is done and the snow has settled. Having actually dug a proper snow cave, I know they're surprisingly effective, and I know how to do it right. It'll be far better than a space blanket for warmth. Besides, I may discover something useful that has been buried. I can always climb the hill in the morning when there is more light, and I'd rather save the flare for getting someone's attention when I know they're looking. Why waste it now on a gamble?