Lived on-board at Hartge's in the West River, a little South of
Annapolis for several years. Had a catalytic heater for the
cabin, and used the yard facilities for everything else. Pump-out, water and power were on all the time as far as I
recall. Didn't do anything with the engine other than run it occasionally - going for short trips. Didn't have an external
shower but draining that would seem like a good idea.
Some folk here are being somewhat negative IMO. Snow isn't that frequent in the area, and rarely very heavy. Worst storm I saw between 1995 and 2002 was less than a foot on the Bay. Left sails on - used them on sunny winter days!
Good
advice about clearing dock. Also keep some snowmelt to hand.
Lots of great little restaurants around that area as well.