I recently booked a campsite inside totality, about 5 hours from here. Going down Sunday, coming back Tuesday.
When we went to see the last one, we did it all in one day. That was a mistake. Traffic on the way there was bad, traffic out after was horrible. If you have a plan to travel for this, it would serve you well to try and avoid having to travel back on Monday, unless you're already pretty close.
Edit: I'll also add - bring your own food and water for your whole trip; do not expect to be able to buy anything on the road, especially on the return trip. We stopped at the sketchiest Chinese restaurant I have ever seen, and they were out of rice.