I went up in a apartment building porch and borrowed a motorcycle tarp I was very warm.
I sort of am a genius on how to sleep warm on a cold night. One way is to eat a large meal about a half hour before going to bed. Then as a persons body starts breaking down the food – it brings up your body temperate 2 or 3 degrees. It’s actually not a healthy way to stay warm – but it is a way. Cheers!