I can be the first to reply to your question, but can only tell you what the weather/crowds are like the week "before" Thanksgiving. When we went in 2002, the weather was in the low-mid 70's to low 80's. It was actually quite comfortable during the days in the parks. We did have to switch one water park (Blizzard Beach) day to another because it was really cool that day. The crowds at the parks were very low, and we hardly waited more than 15 minutes for any ride during peak times. Weather will probably be the same for your trip, but the crowd levels may be higher because it is a holiday week. Also, you'll start to see Christmas decorations throughout the resorts. Enjoy your vacation !