I realize everyone's experience is different, but I will relate ours.
Yellowstone is a BIG place. We did not focus on eating major meals when we were there. We got up early and had a light breakfast (usually cold cereal) because we wanted to get an early start. We spent all day out exploring the park and/or driving to destinations within the park. We usually ate lunch at one of the stops. Sometimes a minor lunch, sometimes a large one (Yellowstone Lodge). We got back to our campsite pretty late. We would either make a relatively simple supper inside the trailer, or we would decide to go and eat at one of the restaurants nearby in the park.
Yellowstone was not a camping experience for us - it was a "let's explore Yellowstone" experience. We pretty much used our trailer as a hotel suite bedroom (the ones with a small kitchenette). When camping at local state parks, etc. we do a lot of cooking outside and inside and sitting around the campsite relaxing. That isn't what we expected to do at Yellowstone. As others have said, if you are at Fishing Bridge (we weren't) there really isn't much room between sites.