Do just what Hydroguy recommends and you will be fine! And I'll see you there, since your trip overlaps my own! Incidentally, I have been that time frame before, the most recent being just last year and it is crowded. But not so much that if you follow those guidelines you won't get a lot done and have a lot of fun in the process. Hours are long, early mornings and evenings are pleasant weatherwise and less crowded. My experience was that once the fireworks were over the crowds got a lot better. Especially if you can make it that last hour between 11:00 and midnight.