Do any of you other Northeast, Northern boaters know of anyone who stays year round on the water? I know in Florida that it is really common, but is it even possible up here? Are some boats insulated? Have heaters? ???

Sure, we put bubblers around boats and pilings so the ice doesn't freeze around them. Some people live on small barge type of motorless house boats year round.

I've had a good friend offer to go in on a 50ish Sportfish either Bertram or Ocean. Are there a decent number of marinas around CT, NY, NJ that are set up with bubblers, allow winter dockage, etc.? Also, is it comfortable? With all the cold from the water would you freeze your ass off, or do these things stay relatively warm?

Every marina uses bubblers to save thier pilings. If you stay just inside of an inlet, the water never freezes because it moves too much.

Is it cold? Jan and Feb in the NE can go from 50 degrees to 0. When it's below 25 degrees, it's cold outside. I'm sure the heater on a Betram can keep you warm.

Look on a chart, Manasquan inlet (NJ) is nice and plenty of boats in the water all winter long.