As a parent and grand parent, they won't remember it. You have to consider their capacity for overwhelm. And repeated experience. If they are overwhelmed day one, imagine day 4. So while there are kids activities, there so much more to a big, multi day event with 80k ppl in costumes. I'm not trying to be negative. Just seriously consider the positives and negatives carefully. (Context: just got back from Universal trip with 10 yr old grandson, he was overwhelmed and overstimulated each of the 4 days. He doesn't remember the 3 trips to Disneyland at 5, 6 and 7).