As has already been mentioned, plan, plan, plan. And trust me, your best advice is to listen to the experience found at DIS.
Thanks to these forums, I've survived Thanksgiving, New Years and Christmas Day at the parks and had a great time! Heck, we laugh in the face of 10's. As long as you know the secrets, you'll have a great time. Again, the secret is ...... PLAN.
Touring Plans does a great job of estimating crowds. No, they aren't perfect, but then again your local weather guy has missed a forecast or two and he's got a degree. Anyway, a 10 for the day is just that, FOR THE DAY. If you want to enjoy whatever park you choose, especially if its the MK on a holiday, get there at rope drop. Your first two hours will be great, no park ever starts off as a 10. If you plan to stay at that park, schedule your FastPass to begin around 11 am or noon, grab a lunch and enjoy. By the time the crowd gets there, you've scheduled the rides you want. Then, take a break at the hotel pool or a late afternoon nap (my personal favorite). Come back out to the park after dinner and enjoy the evening. You may even be able to score some late evening FastPass on your way out of the park after lunch.
The plan gets better if you can Park Hop. Hit the busiest of the parks at rope drop, but schedule your FastPass at the other park starting at noon. Grab lunch or a snack between parks and you'll be fine.
My last 10+++ was Christmas Day. My girls just had to go the MK on Christmas Day. They knew from experience what it was like, I swear they did this as a challenge. We hit the park at rope drop, two rides on Buzz, two on Space Mountain, Peter Pan, Haunted Mansion, back for FastPass Seven Dwarfs, Nutella Waffle for Breakfast Snack, FastPass Big Thunder Mountain, and had a FastPass for Splash Mountain, but go there so early, we waited 20 minutes in the standby line and were done. As we were leaving the park around 10:45 am, Main Street was so packed we walked through the Emporium to get out. We walked past the hoards that were packed in line almost back to the bus stops. Hopped on a bus to AK which was dead. Until we finally had lunch at 1:30 pm, we never waited more than 15 minutes in line.
Would have never been able to do it without planning and the advise from DISers.