We bought sausage from the campground store and grilled over fire. Pancakes and eggs for dinner. Same thing as you, trying to keep it simple to maximize time in the park. We did hot or cold cereal for breakfast and kept sandwich supplies in the truck for picnic lunches. Grand Teton has some nice picnic locations on the water with mountain views. I couldn't give you specifics but it was on the north end of the park, on the right as you head south. Multiple picnic areas. Pulled out the lawn chairs and ate PB&J or Ham Sandwiches but one of our favorite memories of the trip because of the view. Hour drive tops from Fishing Bridge if I recall correctly.