LAK makes an important point about hydration.
We would store our water close to our bodies to keep it from freezing, and put it in our sleeping bagfs at night.
Layers and important. At the time, I had a big beard (picture jerry garcia type) in the winter, and would augment that with a bandana to cover the tip of my nose. I wore ski goggle and had a hat that pulled down over the ears.
very important.
Also, for hands, I recommend mittens. Always mittens. In my case, I have fleece windstopper gloves which I put inside a set of Climb High outer mitten shells. Keep me mitten warm while still allowing me to easily take the digits out to manuver things.
When I am up and awake and moving, I have a thin layer of socks on - too heavy on the socks and my experience is I cut circulation off to my feet. Better to go light (or no socks) and get the circulation going. At night, its a different story, and I put on heavy wool socks (which stay fresh by not being word all day).
Layers are basically silk weight underwear, fleece pants and nylon "wind stoppers" or german wool army pants. For the top I have silk weight underwear, a medium heavy wool shirt and then my secret weapon, a Helly Hanson mountaineering sweater (which I've had for years) that is wool with a nylon lining inside to cut down on the wind and reflect heat, a zippered turtle neck and reinforced shouders and elbows.
Jacket is a heavy REI winter jacket.
I carry everything in a Dana Alpine pack for longer trips or a Dana Bomb pack for day trips (they are original Dana packs, back when it was the greatest backpack maker in the world, before being sold to whomeever it is owns them now).
Also carried an avalanche shovel - not for avalachnes (though they were a slight risk in the White Mountains of New Hampshire) but for digging out snow caves..