I've always been a t-shirt only guy. Recently got my wife to stop wearing panties under her nightgown. She sleeps very deeply, so now I can sometimes play with her pussy during the night if I can't sleep, and she never knows.
I always do except when grandkids are over that might want to crawl in bed during the night.. I roll over a lot and hate when the shorts get twisted and tangled on the delicate parts.
Not normally but I'm always cold. Sometimes after sex we'll fall asleep nude but not normally. Think this is more a male thing because of hormones. I read a research study that said women perceive temperature as about 4 degrees lower than men. So 70 is felt by a women the way 66 is for men.
I had always wore just underwear up until a couple of years ago. Now I sleep naked year round. It just feels better...
I sleep nude all the time and you should just go for it. You will have one of the best nights sleep when nude. If you are concerned about others in house hold then keep shorts you can slip on if you need to get up during the night.