We are in the planning stages right now. I've never been, a few coworkers have but they are hotel people. I am taking the TC and my family loves the outdoors, animals and hiking. We are thinking early...
We spent 8 nights there this fall and stayed the entire time at Madison campground. My recommendation is you pick 2 different campgrounds for your stay. The park is huge and you will spend a lot of time driving. Stay in the park and bring a generator to recharge batteries 8 AM to 8 PM. There are a lot of visitors and an early start to the day is advised. I did get tired of looking at thermal features after the first 4 days. I loved the canyon area and could have spent more time there.