Since 2003 I have lived in my ship in the inner fjord of Oslo, Norway. The harbour of Oslo is ice free most of the year. I have a diesel heater that gives air born heat: It keeps the temperature around 20 centigrades and the humidity around 40%. Specifically I put a hose from the heater to the bathroom/toilet, so it is 30 centigrades there.
The only slight nuisance is that I must fill water about once a week. The benefits are that I live so central in the city of Oslo that the expenses are saved in that I can walk anywhere.
The ship is a wooden ketch, oak on oak, buildt in 1935, gaffrigged with 7 sails, topsails om both masts above the gaffs, three foresails, fock and two jibs ( I do not know what they are called in english) Volvo MD47 for engine.