Would 2 days / 1 night at Universal be enough?

[Kidd McFluff]

Late August is a great time to visit as most US children are back in school and so the parks are much quieter during the week. It's possible you might get a storm or two but on the whole you are unlikely to need the express passes for too many of the rides.

We did wait 30 mins for Escape from Gringotts and The Hulk but other than that most rides were less than 15 minutes queuing and many were a walk on.

You could try one of the less expensive hotels like Endless Summer for a couple of nights. You get early entry to the parks here and they have shuttles so parking isn't a problem.