I am lifetime WW member plus I also work for WW and have had many enjoyable trips to Disney being on WW enjoying all my favorite Dinsey foods.
First of all, whether or not you know it, you will naturally make better choices while at Disney simply from habit of being on WW. Also you will find some of those yummy treats you used to scarf down will over fill you and make you feel uncomfortable and you will not want to eat as much as you will get full sooner. All wonderful benefits of being on WW and being used to eating healthier and better portioned meals.
When I go to Disney I don't worry about points or tracking...I go to enjoy myself. I allow myself to enjoy a week of the foods I want and not feel guilty or bad if I come back gaining some weight. I am naturally more active at Disney especially since I lost the weight and again, my food choices are better than they were pre WW and I can't eat as much. I enjoy myself knowing when I get home I will go right back on program and whatever I gained will be recycled and I will lose it. If you want, at your first WW meeting after your trip you can do a no weigh in if you don't want to see the gain. As long as you go to your meeting and get right back on track you will be fine.
And as strange as it may sound, you will want to go back on program after you get back. After a week of eating foods you usually don't you look forward to your salads and fruit and power foods as too much of good thing leaves you feeling over full.
As pp said...it's a journey not a race. Vacation is a time to have fun and step out of your every day reality - we all need it. You will be more aware of what you eat because of WW but don't obsess over it or feel bad if you gain while on vacation....have fun and know that WW is there as your anchor when you come back to reality.
Have fun!