Don't worry about distances from attractions. You do the parks in loops. So while one campground will be close to something one day, it's going to be the furtherest on the next loops. For example when we stayed at the fishing bridge dump once, it was further away from Old Faithful then Grizzly in West yellowstone. Same goes for Mammoth Hot springs.
Don't worry how far anything is, it's just a great ride. A tip that worked well for us. When you see a people jam gawking at animals, we would drive past the crowd. A short distance down the road would be all the animals that fled the crowds running into the fields trying to get selfies with the animals. Time and time again we were alone with a herd of bison.