This kind of question comes up all the time and it's really subjective. For instance, someone just commented that the first day of Halloweentime was crazy busy, but someone else said it seemed reasonable for what they would expect. That's the key. If you're going to go during Thanksgiving week, you have to be prepared for crowds, and then you're pleasantly surprised if it's not as bad as you think it is.
Our family only goes during "crowded" times since I don't like to pull the kids out of school. We have done the Thanksgiving week for the last three years. Of your dates, I would say the Wednesday has the potential to be the worst with regards to crowds. Thanksgiving itself isn't too bad since many people take time out for special meals. If you want to experience dining at one of the DLR restaurants on Thanksgiving Day, you will most definitely want to book ahead. Disney should start taking Thanksgiving bookings at the end of the month, probably the week of Sept. 26. Many people say the Friday after Thanksgiving isn't too bad. I still find it very crowded but not as bad as the days before Thanksgiving.
Four adults without mobility issues shouldn't have too much trouble navigating the parks. Make sure you arrive very early each day. Use your magic morning if you have one. Utilize fastpass. Go with a good attitude. You should be fine. It is really fun to be at
Disneyland and experience all the holiday festivities.
I usually tend to be on the "Wow! It was soooo crowded!" side of things, so it surprised me that I was in the "It was not all that crazy" camp for yesterday's Halloween Time opening!
