Thanksgiving was the last day of our vacation 4 years ago (so I can’t help with information about Friday & Saturday), and the crowds were huge. We left the park around noon, and I remember it being really difficult to move around the park and that the standby time for Splash Mountain was 105 minutes. It was a different park then though, Space Mountain & BTMRR were down and Nemo and Buzz Lightyear did not exist. Maybe the crowds will be spread out a bit more now than they were then. We are from WA and generally go during spring break or Thanksgiving, and that Thanksgiving day was by far the busiest we have seen.