We were at WDW on T-day a few years ago. Here what we did:
Entered AK at 9 Am as it opened. There were many people waiting. We went to the animal training session show for Pocohantas, then saw the regular Pocohantas show. Walked out of the park at 11Am.
Took a break at our hotel and then entered MGM at 2 PM. Did Playhouse Disney, the One Man's Dream exhibit and movie, saw the parade, had dinner an watched Fantasmic. After the show(6:30) we went straight to MK to see Mickey's Twas the Night Before Christmas(7:45). We started to leave but got cought near the castle as wishes started and could not leave b/c of the crowds and no light to see our way around all the people . You could not move. we finally walked out at 9:10. That was our last park day.
The day before T-day was crowded tooby mid morning. We were at MK from 8-10:30 and did 7 rides,. As we left, there were so many people coming in. We went back to our hotel and then to Typhoon Lagoon for the afternoon.
Sorry, I could not help you with Epcot. We were there the Tues. before, the crowds weren't that bad.