My data is a little out of date, since it has been a long time since I was at Disney (10 years), but at that point, the kennels were just a cage - stacked 2 high I believe. Some where larger than others (ie, double size). We would kennel our Irish Setter & mixed breed. The Setter was probably in the range of 80 - 90lbs, and she had enough room to stand, turn around etc, but not much else. We actually ended up having the two dogs in one cage once, since the mixed breed was very unhappy on her own (she was smaller - maybe 40lbs...).
You are responsible for walking & feeding your dogs, so if you are going that route make sure you have someone who doesn't mind leaving the park in the middle of the day to tend to the dogs needs, as well as a morning and evening walks.
I always found it hard going in to get the dogs for the walks - all the dogs start barking and getting so excited each time you walk in - our little mixed breed of course was the loudest and most frantic... I know they didn't like going back into the cage, but I'm sure it was better for them knowing you are there rather than being left on there own for a week or two.
I hope that helps.
Sandra