I would suggest not doing it. First, you are effectively advertising a commerical interest in the classroom. Disney, after all, is a corporation whose primary puspose is to make a profit for its stockholders (not that there is anything wrong with that). Second, you may inadvertantly antagonize students and possibly the teacher who may not be to afford to go to Disney or who's family have decided that pulling their kids out of school for vacation is not right (I'm not opining on whether that is right or wrong). Third, while this is a well intentioned idea, it fuels the on going race to meet or exceed our neighbors - similar to what some people do in throwing elaborate birthday parties and such.
I would say enjoy your family vacation, and don't feel the need to spread the joy. Every family has its own ways and times to own enjoy their own family vacations.
Have a great vacation!