These are all great suggestions, and I think your idea is a great one. One thing to keep in mind, though. Your note indicated that you were going to do some work on your own time. If that work requires Internet access, be aware that you will not find convenient internet access in many/most national parks out west. And if your plan is to use cellular data, coverage can be very thin to non-existent, especially if your plans include Yellowstone. You'll likely have better luck at private campgrounds outside of the parks, but not only will your costs go up, but you'll also be missing the wonderful experience of camping inside of the National Parks.
