both saturdays within your listed time period will have larger crowds in the parks, both of them.
the 17-18 studios should not be crowded but ioa will have regular pre summer crowds.
i'm looking at the cost of the epp for your dates.
ioa shows their costs at $39.99 both days
on the 19th thru the 22nd, prices for both parks are at $39.99.
when both parks have the same cost for the epps, it makes me think the crowds are starting to roll in......
but crowd levels for your dates are not bad compared to summer crowds.
that should start up the end of June.
i would aim for going to the darkside on the 17/18th.
you won't need the epp for the studios side on those dates.
the ioa will have more peeps in it.
don't buy the epp until you are in the park and judge the wait lines.
use single rider lines and you will not have long waits for rides.
the epp's are higher when they are most needed.
being at about $40 means moderate crowds.