I can't tell you much about a sailboat, but I am a full time
liveaboard, that winters in Philly also.
I have a 440 Aft
Cabin, and here is what I use for heat:
Aft
Cabin and forward Stateroom, have built in electric heat.
In the
salon and
Galley I have a
oil filled radiator (One Each)
In the
engine room I use a small electric
heater.
I find keeping the
engine room warm, goes a long way in keeping the rest of the boat warm.
The aft cabin and forward stateroom, use their normal thermostats. The two
oil filled radiators are plugged into a outlet with a thermostat built in. I found with out that the boat was way to warm.
I do not winterize my fresh
water system, the water tank is under the
bed in the aft cabin. Even with the brutally low temps last winter it was fine. I haul water to the boat in a 100 gallon tank. Most of the time i live on between 65 and 100 gallons a week.
All of my windows get the 3m Shrink Film over them. It was one of the best things I did to insulate the boat. I am luck over 1/2 my boat is double walled one way or another. Cabinets, built in drawers,
wiring chases etc. That helps a lot.
Where do you keep your boat, let me know if I can share anymore information with you.
Scott