First, a couple of basic facts:
1. July 4th is THE top day for attendance numbers at
Disneyland. (NYE is 2nd.)
2. There are 2 attendance cut-offs:
- The first is Disneyland's own limit. The result is that they stop selling tickets and no new guests are allowed in. GENERALLY, on-site hotel guests and re-entry are still allowed.
- The second is the fire marshal's limit. The result is NO ONE enters.
3. Once limits are hit, people can be allowed to enter again if a large number of people leave, but on the 4th of July, I would not count on this.
As for making the best of the day once you are there: Just accept the fact that it is going to be VERY crowded with long lines everywhere and crowds at every show, parade, restaurant, restroom, etc.... It is a day to just go with whatever happens, not a day to have a plan with a checklist and itinerary.
Oh, and if you stay until after the fireworks and are parked in the parking garage or lot, know that traditionally the exit crowds are such that the trams do NOT run for while. Rather, there is well light and staffed walk back to your car. There are just too many people leaving for the trams to handle. If you don't care to be part of the "cattle" heading back to the cars, hang in the park a while long and then go.
Best summary of advice for the 4th:
- If you enter, don't exit until you are willing to accept that it could be the end of your day.
- Know that it's going to be VERY crowded, and just enjoy the day.
- Have fun. It IS Disneyland, after all.