We did a one-day blitz arriving at 1AM on the day before, one day in the park, and left bright and early for the Thanksgiving feast at my folks place in Wrightwood. Obviously we didn't do any Thanksgiving things there, so I can't speak to that. Knott's has a great traditional Thanksgiving dinner (call ahead to get ressies early) and the park is fully operational too.
At that time, we stayed at the DL Pacific and walking into the lobby as weary as we were and seeing the Christmas tree was incredible. We had our 1YO DD in tow, so it was a pretty easy pace for us. Plenty warm (shorts would have been nice), but the crowds didn't seem bad at all, probably 5 minute waits for PoC and Small World (the holiday makeover is complete by then) and no more than 15 to 20 on the major attractions.
The decorations are great and it was a really fun way to kick-off the holidays.