I live onboard!!
I spent my first winter onboard my 2003 356.The size is different but I think the problems would be close to the same.The problems I had was:1.Condensation.I had problems with condensation from the windows.I havent found a solution for that except wiping them alot.Also,I had to remove my V berth cusions because the sides of the mattress that were against the hull,got moldy.Also,I put some of those West Marine round dehumidifiers in the V and the Aft cabins and they helped some.Another problem is that the storage areas under the seats in the salon and anywhere else they have access to the hull.get condensation.I think for next winter I will cut air vents into these areas so cabin air can get in there.2.Heating.I have Reverse Air for heating but when the water temp gets too low(under 50)it doesnt work that well and runs all the time.So I had to use some little space heaters that were controlled by a thermostat and had anti tipping shutoff while I was gone.The space heaters run up the eletric bill a bunch but I wanted to keep it warm.The Reverse air does still come on but it blows the heat from the heaters around and then shuts off.3.Winter water.This is a pain in the ass but it is the price I paid for the life I chose.Once the water is turned off(I had no winter water where I was),I had to haul water to the boat.I bought 3 8 gallon cans and put 24 gallons a week into the tank for dishwashing and such.Showering is not done on the boat and between the bath house and the gym ,I was able to shower everyday and keep my water consumption low.I know what conservation is,thats for sure.Well,I hoped that helped.One more thing,because I lived on the boat during the winter,I didnt winterize the engine or the water systems.Good Luck