Hi Kim,
December is a magical time to visit Walt Disney World Resort. The whole Resort dresses up to the occasion and you definitely want to set up some time to experience
Mickey's Very Merry Christmas Party.
It seems that you currently have two separate reservations. A room-only one for your arrival day, and then a
Magic Your Way Vacation Package with Theme Park Tickets and Memory Maker. Although Theme Park Tickets are attached to your vacation package, you can request them up to three days in advance by visiting
Guest Relations at the entrance of one of the Theme Parks, or Disney Springs. You should have no problem activating Memory Maker and receive all pictures taken on your first day. Also, note that you will not be able to book advanced FastPass+ reservations for that first day. Same day reservations will be available once you enter a Theme Park.
Although you will need to check out by 11:00 a.m. from the first hotel, and the room from the second reservation may not be ready until 3:00 p.m., you can still check in early and take advantage of everything your Resort hotel offers. If your vacation package includes Disney Dining Plan, the meal entitlements will not be available until your check in of your second hotel.
I would still suggest you get in touch with a vacation planning specialist at (407) 939-1936 to verify if there's any availability and simply extend your stay. If not, there could be another Resort hotel that may be available.
If you have any other questions, feel free to come back to the Disney Parks Moms Panel. We're here to help.
Ricardo.