Hi Rebekah,
Mickey's Very Merry Christmas Party is a fantastic way to enjoy the holiday spirit! Your question is a bit complicated because a good view for the shows at Cinderella Castle is not necessarily a good view for the fireworks and castle projection shows.
If the shows at Cinderella Castle are the priority for your family, you will want to be closer to the castle. You will see people stalking out their viewing spots very early. Places along the curb are at a premium. It's important to remember the parade will not travel on the section of the central hub between Liberty Square and Main Street, U.S.A.
If Celebrate the Magic and Holiday Wishes-Celebrate the Spirit of the Season fireworks are your priority, you will want to be closer to where the hub meets Main Street, U.S.A. Being a little further away from Cinderella Castle during these shows allows you to see more of the fireworks going off around the park.
If you want a decent spot for all of the above, your best bet is to be somewhere along the curb in the hub. I'm sending you pixie dust that you find the perfect spot for your group!
Thanks for stopping by the Disney Parks Moms Panel. Be sure to let us know if we can help you with any other questions!
Wishing you a magical visit,
Amy H