During my 22 years in the Air Force, I knew several individual who did what you're looking to do. Again, you can do it in the more northern states, but it can be tough. Most of the guys I knew that pulled it off in the states with cold winters did so in 5ers, with skirts and sited in mobile home parks. My son in law has been working out of his 5er in an oil field right up by the Canadian border in North Dakota for over a year, and for a year prior to that he was in one of the colder portions of wyoming, so it can be done without to much trouble if you take the time to pick the right camper, and set it up for the weather. Heating won't be cheap though, as my son in law goes through a lot of propane, spending several times more than I pay for gas to heat my home.
We went to fulltiming and went with the fifth wheel for a couple of reasons.
It gave us an extra vehicle. My wife drives the car and I drive the truck that pulls the fifth wheel. Not an issue for you now, but maybe in the future.
If something in the motor or transmission breaks, I don't lose my house by taking it to the mechanic.
It breaks the systems down in my humble opinion, into more manageable parts. My 12 volt system on the fifth wheel is much less complex than the one in a Class A or Class C. For you that might not be an issue, but for me it was.
Space. It seemed like I got more space dollar for dollar in a fifth wheel. Again, I am one of four people with a large dog. Space was a big consideration.
Again, thanks for your service.
I am in the Air Force and live in an Arctic Fox 22H model travel trailer with me and my wife. It has plenty of room for us and the best part is being one mile from work and literally accross the street from the gym. We are here in Utah, so it gets pretty cold in the winter and it does fine with full hookups. Just have to put in some heaters and skirt the thing.