We have 3 days for IOA/US. May 16,17,18. We are a party of 4 (2 boys ages 10,14) and we are not staying onsite. This is our first trip to Universal. Will this be enough time to do all the major attractions? I was planning to spend 1 full day at each park than on the 18th spend most of the day doing favorties. We change hotels on the 18th (leaving at 5PM) as we are spending 2 days at WDW (may 19,20). Any advice? Thanks