We chose a one day tour with a local company, 10.30 hotel pick up and return after the evening fireworks. It turned out to be a very long day for two more  mature  adults. The weather was hot and very humid. Plenty to amuse the kids but less of interest to us. The park was not very busy and popular rides generally had only small queues so we manged to do what we wanted with plenty of time to spare. 4 to 5 hours would have been enough. Food and drink is quite expensive, and you can't get a cold beer, at least not where we ate.