I would leave NH by 7:00 a.m., drive according to the conditions, and pull into a Flying J, Pilot, WalMart around 8:00 p.m. (Campgrounds in January are probably closed) Everyone there (Flying J and WalMart) will be running their engine or genny so you can too. Trucks will be coming and going all night so you might need a battery powered radio for "cover-up noise"
In January, your goal is to get out of the dangerous driving areas (due to weather) as quickly as possible. Stopping every couple of hours will keep you refreshed. Take a nap for an hour at a rest area that looks safe and secure.
Take water from home for drinking and cooking. Take 3 - 4 gallons of pink RV winterizing fluid to use in the toilet and bathroom sink. When washing your hands: use 2 glasses of wash to wash and follow with 1 glass of RV winterizing for your grey water holding tank (probably not necessary for an occupied MH for your 2 day ride to warmth).
Night #2 may also necessitate a Flying J or WalMart. Night #3 should be at a campground. Test the water quality at the CG and de-winterize your MH for the rest of your trip.
Heading west from Jacksonville should be frost free. Keep close attention to the elevations. You probably don't want to stop in the area of west Texas and New Mexico.
Take your time and be safe.