Hi, Rebecca!
Congratulations on your Disney Dream vacation in December! You're in for an extra special treat on Disney's newest ship to sail during the holidays!
In terms of pinpointing an exact departure time from your resort and an approximate arrival time to Port Canaveral, it's going to be a bit of a guessing game until you arrive and check in at the resort.
Disney Cruise Line (DCL) Ground Transportation varies from day-to-day depending on the number of DCL guests leaving from Walt Disney World and the location of the various resorts where they are staying. Yet, you can guess that with the port opening around 11 a.m., you'll probably be given a departure time around 8-10 a.m. Your exact pick up time will be given to you once you arrive at Animal Kingdom Lodge/Kidani Village.
To choose your port arrival time online, simply choose the earliest available time. This is just an approximation in order to anticipate the arrival of the largest influx of guests allowing the port to be ready to handle the crowd.
Let me know if other questions pop into your head before you sail. I'm here to help! Have a wonderful day and a magical vacation. Bon voyage!
Andi