I'm guessing you realize that there are more pools SOUTH of the Mason-Dixon line, than NORTH of it? And, that winterizing pools in Georgia (where I am) is a bit different than winterizing them in Maine?

I know it's typical to drain 2/3 of AG pools in the US Northeast, but not a lot more than that. I think equipment is often completely removed (except for sand filters) and stored indoors.

But as I said, I have no experience. Pools don't freeze solid here . . . and they do, there. Consequently, the best answers you're going to get are likely NOT on a forum, but locally. In fact, your first winter, I'd STRONGLY recommend HIRING it done by someone with LOCAL experience, if that's an option. And when it's done, make sure you are present and taking notes!

Good luck!