Hello Witherig and welcome!
Jerry is correct. Yellowstone has changed over the years. Partially to accommodate the volume of folks that visit, and partially out of respect for fires and volcanic activity. It is worth the experience. You most likely will have to save the campfire experience for another campground as you travel to, or back home.
We always chose the off-seasons to visit popular parks, specifically to avoid crowds. Visited Yellowstone five years ago in mid-May and were rewarded with a fabulous overnight snow while camping at Fishing Bridge. At the time we had a middle-aged rotty traveling with us. She was silent, and preferred avoiding crowds too. Perfectly content to sleep on the couch while we went on short hiking, sightseeing, photo excursions on foot.
The campground rangers kept us informed of bear activity so we could walk with her without issues in the early mornings just around the campground. I would not recommend taking a dog on the trails. There are buffalo, elk, moose at Yellowstone. They are not fenced-in, nor domesticated. I don't know about your dog: but ours was absolutely facinated
with such unfamiliar smells and critters. No way did I wish to create an incident: dog vs miffed buffalo!
Buffalo will put up with us taking pictures...but an excited barking dog...not so much.
I am curious, so please don't forget to log on and let us know your perceptions of Yellowstone after so many years.