Truthfully, I wouldn't do it in NORTHERN NJ.
I'm fulltiming in Southern VA, 12 miles from the NC border. Winters are at worst six weeks of freezing cold weather. Two refills on the propane tanks, a small ceramic heater and a heat pump/air conditioner get me through just fine. You're area? Three months of bitter cold.
If you're just looking to save up money for a year or two, then the "park model" and the trailer park ARE a better solution. If you don't tend to meet people, who cares who the neighbors are as long as they aren't running a meth lab?
As for the "not meeting people" - that's a choice. In almost any campground most people are friendly if you make the effort to smile and be friendly. (And if you do meet the "people of the corn" - you can move out in the middle of the night.
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IF however, your job would let you telecommute (even just from Nov-Feb) then an Airstream is a distinct possibility. Before you do anything else, I'd recommend a day trip to Colonial Airstream a bit to the south of you. Take a serious look at their inventory up close and personal. The DO sell a lot of 2nd and 3rd Airstreams.... so they take some trade ins!
If you are dead set against buying a serious tow vehicle, and only want to move it once in a while, rent a truck for the moves, or even pay to have it moved. I have a 2500 Diesel Silverado to pull my rig. Reality check is that I'm going to have to buy a gas-sipper for a daily driver. I'm thinking a Honda that I can put in the bed of the truck. (YES Terry, I will be super careful! I had my first motorcycle license in 1966 and still have all my fingers and toes.)
Paula Ford