I wouldn't if you are hoping to get back into the Magic Kingdom afterwards. I would think that the crowds will be quite large by then and you'll have lost an opportunity to steak out good spots for fireworks viewing.
However, if you were hoping to view them from the beach area at Fort Wilderness or even plan on taking the boat over to the Contemporary for viewing, it sounds like a great idea.
I doubt that they change much about the show itself though just because it is the 4th.