Hi Jennifer,
You are going to have so much fun at
Mickey's Very Merry Christmas Party!
You can view a copy of the Map from last years party at www.wdwinfo.com/holidays/photos/MVMCP-map.htm which lists all of the rides that were operating during the party. As you can see, many of the popular attractions were available and I would expect it to be very similar this year.
The event officially takes place between 7.00pm and 12.00 midnight on select nights in the Magic Kingdom. Guests have been allowed to access the park as early as 4pm using their special event tickets in the past but there is no guarantee that this will be the case this year.
It will be a long day if you do decide to visit the Magic Kingdom early that morning and stay for the party but it is entirely up to you.
If you do decide to spend the day at Magic Kingdom as well as attending the party in the evening, I would recommend that you concentrate on the rides and attractions during the day and then focus on the special events that only occur during the party once it begins.
Here are my recommended must-do parts of the party to experience:-
1/ The enchanted Castle Dream Lights on Cinderella Castle
2/ Mickey's Once Upon A Christmastime Parade featuring Santa Claus himself
3/ Holiday Wishes: Celebrate the Spirit of the Season fireworks extravaganza
4/ A magical snow fall on Main Street, U.S.A.
5/ Meet and greet opportunities throughout Magic Kingdom theme park with some of your favorite Disney Characters
Wishing you a magical trip