Just be aware that last Christmas was COLD and crowded. I mean--I live in Michigan and we spent some mornings and evenings huddled in gift shops bundled up in heavy coats and gloves because it was just so freaking cold! I kind of prefer to go to Florida when it's hot or at least warmer than Michigan.
And when people say crowded they mean CROWDED. I literally made DH and my 14 yo DD hold my hand when we were trying to get out of MK one day the week of Christmas because I was afraid I would lose them. I can only imagine trying to keep track of little ones.
We went for 2 weeks and that was fine--we were able to go in the mornings and not have to worry about not seeing everything and spend more time at the hotels. It was great for Christmas but DD has requested that we not go again at Christmas time because the crowds freak her out.
By all means, give it a try (I'm glad we did but never again) but I thought I was prepared but I was still freaked out by the crowds. There were days when we literally felt like we could not move--it was just this mass of humanity.

Just be sure to make PS's for every day you're there. We saw a ton of people being turned away from every restaurant we went to because they did not have a PS. My family usually mocks me for my obsessive planning but they did love the fact that we had one sitdown meal every day guaranteed.