Hi Chris,
Yep, that's going to be a very busy time to visit the canyon, but it is possible to get away from a majority of the people. I would suggest Lipan Point, Moran Point and Yaki Point for sunrise and Desert View, Yaki Point and Mohave Point for sunset. One thing to keep in mind about Yaki Point is that you have to ride the shuttle bus to get there. It can also be very busy, but you can walk a hundred yards to the east of the point and have a nice area to yourself. Also, The rim walk between Mather Point and Grand Canyon Village will give you several opportunities to avoid a majority of the crowds.
I'm sure I'll think of a few others and will update the thread with new posts as they come to mind. Please let me know if you have any questions. Check out my website for my Grand Canyon work which I created last month while I was there as the Artist-in-Residence.
Adam