I have a crowd-aversive son, and last year we used two strategies that both worked great. 1--IMO, only MK is worth getting there at rope drop, because of the show. So we went CRAZY early--carrying those Little Debbie mini muffins in bags for breakfast. When we got there, people were barely starting to trickle in. Bag check was fast because we were like third. Then we got right up front against the entrance and plugged him into his tablet. The crowds gathered behind us, but we were careful not to let them get in front of us, too. He remained pretty oblivious, with his noise cancelling headphones and tablet to distract. We only "woke" him when the train pulled in, watched the show, and rushed in as soon as the doors opened. Our first stop was the Customer Service desk, to get
DAS (which is off to the side, and quieter), but if you don't need this, I'd get through and off Main St asap--head straight for a ride. TONS of people stop for that first photo in front of the castle, or to see the characters in the square--so if you just push through, you should avoid that overwhelming crowd feeling. I don't feel like any of the other parks are worth rope drop, so we just arrived about 30 minutes later than opening, and the crazy crowd was dispersed. Both worked fine for us. Good luck!