Here are some ideas from when I used to go winter backpacking:
Keep you boots inside in a plastic bag so they are not like concrete putting them on the next morning
Keep the next day's socks and underwear in your sleeping bag so they are warm when you need to put them on
Have a filled water bottle nearby and a porta-urinal container so you don't have to leave the teardrop in the cold, dark middle of the night. And make sure you can't confuse which is which in the dark...
You lose most of your heat thru your head and neck - bring a knit hat to wear, even to bed if that's what it takes to stay warm. A turtleneck dickey provides a lot of warmth for little bulk and weight, and is easy to take off it you get too warm.
Higher fat foods help you generate a lot of heat and stay warm. If you are cold when you're ready to turn in eat a piece of cheese or (ugh) a squirt of butter or oil
Don't eat any yellow snow
Lastly, remember that a careless mistake that you'd think nothing of in the summer can cost you your life in the winter (at least in the wilderness - maybe not so much when TD camping with a vehicle nearby...)