I'm also located in the mid-Bay and other than for a big snow or an ice storm (which could be a scary dangerous thing), I could probably leave the boat in the water and side-step the expense... but I'm not going to.
Four years ago I put a new bottom on my boat and two years ago, did it again. You would think I was good-to-go, right?
Nope. Last December when the boat was pulled and power washed, about half the bottom came off again.
The job had been done by two very reputable yards, so we got an opinion from the rep of the paint company...
The bottom was sanded completely and was prepped and painted using the paint company recommendations.
When she comes out this year, we are really going to be inspecting her bottom!
Point is... Although I pull the first week in December and go back in the first week in April, I take that time on the hard to go over everything, and I service or repair anything that needs it.
After service, she gets cleaned and waxed, because you can't do that in the water.
I just see my winter lay-up time as part of my normal maintenance cycle.
Is it required? Absent a big snow or ice storm - no. But it is something that I feel that I need to do.