The Chesapeake is the only real problem. Once you get to Norfolk it's considerably warmer. The marinas
will be running pretty normally. You can dock
every night and run the heater if you don't mind the dockage fee. At smaller marinas
you might find the overnight rate is very negotiable.
I'd get one of the oil
filled heaters for the trip. The little fan ones are not meant to run steadily and can catch fire.
you could get one of these camp heaters and a bunch of the 1lb propane
cans. These put out a lot of heat. Make sure there's some ventilation and pick up a carbon monoxide sensor at Home Depot. Don't run it when you're asleep.
Century 2317I 14 000 BTU Heater/Cooker: Camping : Walmart.com
The toughest cold will be underway in the cockpit
. It's the wind
chill. Dress for skiing - long underwear, facemask and goggles. Get those little chemical heat packs to put in gloves and boots. Does the boat have a dodger
That said, most of the days will probably be quite pleasant and pretty. Certainly no crowds