Earlier quoted context omitted.
Actually 32F without wind is no big deal if you have a decent sleeping bag. Plus it gets warmer as you do more stuff inside (e.g., cooking). Igloos have the same design and can get pretty warm. [0] The real problem in my experience is that it's quite humid. Since you are insulating with snow it evaporates and raises the humidity up to the dew point. [0] https://en.wikipedia.org/wiki/Igloo
I guess it varies from individual to individual. I can be out in 110F weather all day comfortably if I have enough water and a large hat but have very low tolerance for the cold.
Even quite mediocre sleeping bags (by modern standards) are positively toasty at 32 degrees. It was common in my group for people to sleep in their underwear in the caves! Our sleeping bags were 0 degree rated, though.