In the 15 years of our nerd-dom actively going to the parks (with kids), we have 3-4 trips that were exceptional in terms of crowds.
One year we arrived the weekend AFTER Thanksgiving, and it was nuts. The kids literally rode 7DMT a dozen times one day.
Two years in a row, or maybe 2 out 3, there were big hurricanes barreling toward Orlando. We live within driving distance, so we gambled and won. It was amazing!
After the parks re-opened, our first visit late summer was a dream. 35 minute wait for FOP. I thought it would be like that again... nope next couple visits, pre and post Genie, were elbow to elbow humanity. We still got to ride every single ride, but the waits were long, and honestly unbearable if you add in the breakdowns.