You did not indicate if you'll have access to shore power or not.
Heat will be your biggest challenge. We enjoy driveway camps in the winter, especially week-ends, and our new Outback functions far different than our old Springdale. First, it takes a LOT more propane to heat, and we run 2 electric ceramic heaters to help boost it "over the edge". Winter is just starting, and we've already been through 3 - 30 pound tanks since we've purchased the Outback in September of this year, and one tank is empty right now (getting it refilled today).
Your windows may have a tendency to fog up and ice over. One thing I noticed with the closet slide (our Springdale did not have any slides), is the closet itself is very cold inside, and the edges around it, are very cold also. I see the potential for this area to sweat also.
If you're in a snowy environment, you'll be dealing with wet boots, shoes, and clothing. You'll need some way to dry everything when you come back into the camper. Not sure how you'll do this, but it's something to think about. Leaving boots outside is not the answer. Who wants to put frozen shoes and boots on your feet? In the Army, when I was in Korea, (1984-1985), when in the field, we were told to always hang our clothing up in the tents to dry out over night and sleep with as little on as possible to avoid sweating in our sleeping bags. Wet clothing in the field in cold weather was a bigger enemy than the "enemy." Trench foot was a big threat. I ended up with a foot fungus that took the next 20 years to finally clear up.
We use a port-a-potty we purchased form Dicks Sporting Good. Any Sporting Goods store has them. We do not use the on-board water system, or holding tanks. We take the port-a-potty and dump it in the house toilet every day we in the camper. When we ARE actually camping away from home, we dump it down a pit toilet. We don't do "real" wilderness "off the grid" camping at all. If you do "off the grid" camping, you can probably just dump it on the ground, or if your able to dig a hole in the frozen "tundra", dump it there and when you leave cover it. We did this in the Army too.
Water will be a challenge, but you'll soon learn how little water you really need. Take lots of baby-wipes for clean up. Which bring up disposing trash. If you're in a campground, you'll probably have dumpsters and can probably burn in a fire pit. If "wilderness" camping, you can burn everything except your metal items. You'll need to carry them "out" with you. Be responsible.
And if you smoke, don't throw those cigarette butts on the ground! .. anywhere! That's just plain rude, stupid, and selfish! Not to mention a fire hazard... even though people who do throw butts on the ground don't think so. I've seen 2 fires started around businesses when someone tossed a butt into the bushes and mulch!
Here again, if you electric shore power, it will be much easier than if you have to run off a generator. But if you don't mind the noise and carrying extra fuel, a generator will do well. Just plan on making sure you've got good heat and somwehow to dry out.