It's hard to predict how much snow you're going to get. I think water resistant shoes are good to start with, and if it seems like it's going to be a really snowy winter, then go ahead and buy the boots.
I've been in Chicago my whole life, where we have the four seasons all in a day, and I've owned snow boots once. I think (water resistant) hiking types of boots are better to get, you can get more use out of them.
When it's cold, usually for kids, an undershirt, a long sleeve shirt, a sweater and then a jacket is good. And you adjust, according to the weather. So layering is usually enough.
Hats and mittens are key, I think if you're head and hands are warm, you're all warm. By March, you should be out of the really frigid temperatures.
Good luck, and I'm thinking warm thoughts for you.