So, I had to try sleeping in zentai...

I had my leotard suit on. I turned a satin blanket cover inside out so tahat the smoother side came on the inside. Then I put the blanket cover inside a regular sleeping bag. Then I slipped into the blanket cover and noticed that I was in a very warm and comfortable, slippery womb

I had problems getting sleep, I kept waiting for hours. I had toilet breaks and drank water trought the hood. Toilet breaks are easy with this suit, you just have to move the leotard a bit to the side and pull the thights down a bit (no need to open the snaps).

At some point in the night I slept for some shorter periods, and every time I woke up I was happy for already being in my lycra cocoon... wonderful!