I have been a couple of times in November and you're correct when you say its a good time to be there. Usually the sometimes, hot, humid air of September/October has been replaced by cool, strong offshore winds. No mosquitos to speak of and maybe a few sand flies only at dawn and dusk.
The temperature might drop to a point where you may need a sweatshirt or light windbreaker at night around the beach bars due to the cool breeze, but daytime temps are in the mid 80's and the weather generally is really pleasant.
Suggest definite reservations at your choice of hotel or resort at thanksgiving week because it probably will be quite busy then.
Have a fun time ... **Jim
AmbergrisCaye.com 
