Have a great trip! That heat wave that's going through So Cal right now will likely be passing through the Grand Canyon area in the middle of this week; so you might hit pretty hot temperatures down by the river and then through "The Box" to Cottonwood. On a hot day that side trip to Ribbon Falls is even better because you can get right under the falls and cool off.
Please do let us know how it goes. I'm especially interested in hearing how the fall colors are at the North Rim. There are some beautiful aspens at the North Rim.
My permit finally came through for the Thunder River / Deer Springs loop, but I have about 1.5 weeks before I head over to the Canyon.
