Hi Brandie,
The dilemma of the
FastPass+ in the tiered system! However, I think you are on the right track.
If you have anyone who is a fan of Elsa and Anna, you should make
Frozen Ever After your priority. This attraction had four hour waits on opening day. If you can secure this FastPass+, try
Soarin' at the park opening. This attraction has been updated to take you around the world. Test Track has the option of single rider line. As long as you are okay not riding with your group, it is an option.
However, you mention a second day at Epcot which means you can schedule a FastPass+ for one of these attractions on Day 2.
While you are in Epcot during December, take advantage of
Holidays Around the World at Epcot in World Showcase. This is my favorite place to spend the time during the holidays.
Wishing you a magical day!
Beth