Leaving it in the water for winter is not an easy decision. I've done it a few times (on Long Island, similar weather patterns as you).
1st requirement - Get an ice eater to make sure the water around the hull doesnt freeze. Water has to be moving to prevent it from freezing up. Put a thermostat on it and you'll save $$ so that it only turns on when freezing is imminent. They work, but you cant ignore them. One year mine stopped working, I lifted it and found a piece of wood jammed between the propeller and cage around the prop. easy to fix but what if I didnt pay attention or wasn't home? Sunken boat.
I know what its like to take a boat out on one of those perfect winter days. Calm sea, blue sky..you own the water its so lonely out there.
But think about reality - how many times are you going to do it? There are a lot of things to do to make sure all goes well - engine down all the time, drain wash downs, etc etc. For what? A few extra days on the water? Is your boat covered full time? If not the snow and ice build up can make things dangerous at best. My wife has pictures of me shovelling snow out of my cockpit. Its a novelty that wore off very fast. My 2nd home is on Fire Island so it was nice to take a boat ride on sunny days, but the amount of work needed to make sure my ride was in good shape got to be too much. I'm a worrier, but in winter now I get comfort knowing the boat is safe and dry on land compared to the distress of wondering how my boat is doing on the worst of worst days, or when I'm on vacation and no one's around to check on things..