Michigan in January is not a spot I would want to be in.
If possible you may want to move south earlier, and if you must return in January do so with just the truck, or fly in for a while.
On the money side, I sure hope you are overthinking/worrying this. I am in a similar position, we have two prospects currently working at arranging financing on our house. We will hit the road with an all new rig smaller than yours, but only about $2600 a month in retirement income, but with a larger nestegg. Were hoping to travel extensively the first couple years, then settle into a more modest set of moves.