If you're going in the summer, visit the North Rim rather than the South. The latter is absolutely overrun in the summer, and the weather is actually pretty lousy (hot to very hot, especially if you're going to hike into the canyon, and a regularly scheduled violent afternoon thunderstorm that seems to have as its sole goal to rearrange campsites). The North Rim is at over 8000 feet elevation in a lovely pine forest. IMHO, the views are better from there.
The only problem is that there are fewer than 100 campsites on the North Rim, so you'd have to reserve early. But there are several Forest Service campgrounds on the access highway between Jacob Lake and the park.
Another bonus is that you're well positioned to see Bryce Canyon, which is another beautiful high-elevation park. In general, if you're in that part of the country in summer, stay high. And it's easy to do that since marijuana is legal in Colorado.