Hi Barbara!
Those are crowded days, but some planning can make the difference. I always try making the most of our days by knowing where to go and feeling relaxed.
Arrive as early as you can before park opening hour. Early park hours are usually the ones with the lowest crowd levels on any day. I also like really late park hours for lower crowd levels.
If driving a car, arriving early will help ease the process of finding a parking.
Try having breakfast before or while commuting to the parks. Bring good snacks to the parks.
Decide what attractions and activities you want to experience each day and at what time of the day.
Knowing where and when to go will help make the most of your day.
I also suggest enjoying the Christmas celebration and crowds, and not only the attractions.
If you already booked dining reservations that is awesome, if not try knowing what
counter service restaurants your family will enjoy.
Know that it will be a different Disney experience, but certainly one to look forward to.
Thank you for letting us help you plan a magical Christmas celebration at Walt Disney World.
Miguel