Reddit mentions of Allen & Mike's Really Cool Backcountry Ski Book, Revised and Even Better!: Traveling & Camping Skills for a Winter Environment (Allen & Mike's Series)

Sounds like fun! See if you can find a copy of Allan and Mike's Really Cool Backcountry Ski Book, which is largely about winter camping. So, let's talk winter. You need a way to travel and a way to keep warm and dry; without either you're hosed. You also need navigation skills and some adjustments to your stove setup.

For traveling your snowshoes should be slow but functional. Bring some zip ties and long ski straps (e.g. the orange Voile ones) in case repairs are needed in the field.

For shelter, you have your tents which should be fine. The Coleman bags make me nervous (and I don't know what model you have). More importantly you'll need good sleeping pads under you; the combined R-value of them (you can stack them) should be at least 5. Otherwise the ground/snowpack will suck the heat from you.

Butane boils around 30°F and isobutane around 11°F. Below that it stays liquid, which means no pressure for the stove, but even around and above that the pressure will be lower. A so-called 4-season canister mix is often 80% isobutane and 20% propane, letting you push into the 20s, and is most effective when used inverted with a remote canister stove. (When not inverted the percentage of propane decreases over the life of the canister, reducing its benefit.) Other tricks involve putting it in a bowl of cool-lukewarm water when cooking and keeping it inside your sleeping bag at night, and in your jacket during the day. Traditionally people used a white gas stove for winter, as they have a manual pump to pressurize the fuel. Bring Bic lighters and don't trust the built-in ignitors.

Finally, a deep snowpack often means there won't be a trail for you to follow. You need to be comfortable navigating on your own. This means map, compass, and GPS. If you use your phone for GPS, make sure you know how to conserve battery and have the right apps to use it in airplane mode. Use GPS only to fix your location on the map, and use a traditional compass to set your direction of travel.