I've read lots of good stuff about
MVMCP. However, we went last December - in the rain. This was not good. There was no parade and no snow. The only "extra" we experienced was fire works. Of course those were great! It may be a great time ordinarily, but our exerience REALLY did the whole family in.
Snow on Main Street was the thing we were really excited about. Since you're in Wisconsin, I assume snow isn't such a big deal for you. Decide what the lure is for you and then you may have a better idea if the extra cost is worth it.
You do not have to do MK on the day of the party. About 4:00p.m. we went to the front gate, showed our MVMCP tickets, and were given wrist bands to wear. The wrist bands indicated we were allowed to stay in the park after the regular closing time.
I can't speak for the open attractions or the length of lines because I think the rain probably altered that as well as the other festivities. I think the park was open until midnight. For us, this made for a very tired next day.
You really need to hear from some one who's had a better experience. My whining is getting to be too much!
Whatever you decide, have a great time!