We lived aboard for a year at Humbug Marina in Gibraltar, MI, right where the Detroit River meets lake Erie. They have several year-round live aboards. During the winter you have access to the bathroom, showers, and laundry (along with the summer also). With a 22 footer you should have NO problem getting a slip. The only hardship during the winter is that the pump-out is shut down, and the water to the slips is also shut off. Luckily, we had a slip close to the bath-house/laundry and were able to fill our water tank when necessary with about 100' of hose (which everyone used and was kept on a reel in the laundry room. Contact me if you need more info.
Catalina 38, Hull #112
Grosse Ile, Michigan