i always suggest to day visitors to arrive early and go to IOA first.
many many times if the line is long at the turn stile, the TM's will open the gate around 8:30ish.
you will find the rides in the front of the park open.
think coasters to the left and seussland to the right.
if you drive, arrive at the parking garage at 7:40 if the park opens at 9 that day.
you will have such a short wait in that car line but when the garage opens at 8, you will be in and parked within minutes.
you would be at the turnstile at ioa by 8:17 then.
if you start at the studio side and let in early, not as many rides will be open at 8:30ish.
do head for the ones that are open early.
start with ioa, cover what you plan to there, then head to the other park.
to the person that stated they will be there on the 19th, i would assume there would be some crowds that day in the park.
go early, crowds will be forming around 11ish.
eat at off times.
came back to add, you should check with universal to see what time they will be opening if you are going next week.
i read some parks have been opening early due to the crowds. not sure if universal adjusted their times for next week also.
if that is the case, and you are driving to the park, adjust that time also and go earlier.