With your dates, you will arrive on the Sunday of Memorial Day weekend. That day will probably be the most crowded. It's also Star Wars Weekend (not sure if this has been announced as happening yet but if it is, it'll be every weekend in Mary). Monday, the levels will go down as people head home from the three day weekend. You will leave on Saturday, the 2nd. That will be Gay Days weekend so you'll miss those crowds. So, the only days that will have increased crowds will be your arrival and departure days.
It is hotter than the first week in May, usually. You can never tell, though. You'd probably pack the same things for those weeks anyway.