Done it? I worked there when I was young!
Eat tons o’ food. Ditch the diet.
Drink tons o’ water. You should not make the snow yellow when you go. Incidentally, this is one of the Catch 22’s of winter survival. You drink so much water that you’re going quite often. This will necessitate a mid-night trip to relieve yourself. If Hell could be cold, you will experience it when you go to urinate and it’s -15 F. You have to choose between getting all dressed up just to step out and go, or just getting it over with ASAP. Some guys will crawl in their sleeping bags with a container to prevent such trips. I’d rather run outside.
Start getting used to wearing wool right against your skin. If this is totally unbearable, get a set of silk long underwear or some type of wicking space-age material. Above all remember, “Cotton Kills”. One of the first things rescue teams ask before searching for a lost hiker is “what was he wearing?” If they find out it’s jeans and a T-shirt, they don’t expect them to survive the night through.
Wool pants can be found at Army surplus stores. Or, you can check out the Goodwill and Salvation Army stores for wool dress pants. However dress pants tend to be good spring/summer/fall gear since they’re lighter.
Here’s what I would wear. Wool socks with loop-knit insides for plenty of loft (take a second pair). Duofold long underwear with a Polypropylene/wool mixture (not the cotton/wool Duofolds). A really heavy wool sweater. And some wool pants. Over the sweater I’d have a thin windbreaker of some sort. Wool stocking cap. Chopper mittens. Silk bandana around my neck. Pack boots. Then I bring a Mackinaw and maybe a pair of insulated Carhart overalls for when I’m in camp and I’m not as active. The Carharts are cotton canvas but that’s acceptable if it’s the very outer layer and you’ve plenty of wool between your skin and the cotton.
If your leg breaks through the ice and gets wet, immediately roll it in the snow. The snow soaks up water and if you can get the water to soak into the snow instead of soaking into your clothes that’s a good thing.
Tell them “HOL RYE!” when you get there.