Steve,
I am at a private slip in Severn House condos on Back Creek in Annapolis. This will be my first winter out of the water since I bought my boat in 2011. It seems like a lot more work to come out for the winter! For the first two winters I was at Port Annapolis Marina across the creek. They had a 24 hr staff watching the boats and bubblers so I felt OK leaving the boat in all winter. It didn't even freeze over the creek the first winter.
Last winter it froze early and often. There is a dock master for the condo development who walks the docks often and they also have bubblers. My location near the head of Back Creek is very sheltered so I'm not worried about storms. Our usual tide is about a foot but I have seen the boat do OK on it's own with both a plus and minus 3 foot tide due to high winds. I'm at the boat 2 or 3 times a week doing winter projects so I get to check on it often but I'd say now that I've done it that fear of wintering over in the water is mostly mental.
If the slip location is sheltered, there is freeze protection and there is someone watching the boats, I would prefer to leave the boat in the water for the winter. I did say 'slip location', no mooring without power. I leave my shore power connected so I have battery charging to support two bilge pumps. Although I winterize everything but the bilge pumps, I also leave an oil filled radiator type heater on low which keeps the interior above freezing. My boat doesn't leak except for rain water down the mast so bilge pump use is small. Staying in the water has to be much warmer than on land, especially for the first half of the winter. With the oil radiator cranked up and a second small space heater/fan I can get the interior warm in an hour if I'm working inside.
The advantages: no winter haul fees, you can go sailing anytime you want, you decide when to de-winterize and start the season, no waiting for the yard to launch (and haul) you, no waiting for 50 degrees to paint in Spring. I've sailed in 80 degrees in early December and early March.
Your marina will probably will find it too busy to haul you in Spring, I usually do it in August when the yards are slow and no waiting for 50 degrees to paint (2 coats a day at 90F)!
Mark