Hey König, for that reenactment I slept in the hole fully dressed with a blanket over me and two zeltbahn quarters over the hole, the top tied to a sapling with a rope. I only got 2 hours of sleep anyways with fucking Ami probing the line AFTER 2am when my watch was over. There were only 12 of us and about 30+ of you guys. Add in fog and soaked trees dropping waterdrops onto dead leaves everyfuckingwhere with no cease and you'll bet I was one paranoid mofo.
Although for the two hours of sleep I had it was nice out, a bit chilly. Since I had my boots on, my sweaty feet were really cold.
Oh yeah, remain as dry as you can be. Nothing sucks more than freezing from sweat. Also layers count, no matter what it is. That's why straw is amazing because it keeps the ground from sucking the heat out of you as well as cushions the hard ground. That's why typically when I sleep the boots are off and the socks/footwraps around my mid-section. You can lose a lot of heat through your feet too and they need to be well enclosed. I carry around a little bag with me to store extra underwear, socks, and shirts (too many times getting rained on to not know any better) and I like to stick my feet in there.