We solved the crowd issue in OC, NJ by going the week of May 30-June 6. It’s after Memorial Day week, so everything is open…but it’s before school is out so there are no weekday crowds. AND the prices of rentals are a third of the cost of the peak summer season. The ocean water is always cold…but the beaches are just as nice in June (if the air temps are warm enough).
We did a day trip to Cape May last year, and this year we will go back with our bikes.