It is possible to make the trip you plan in one day, but you will miss a lot of the beauty of the park as much of the beauty is seen by taking side roads and your rig is too large to make many of these side trips. Of course you can see these side roads in your toad, but you need to plan on spending more time.
We did Yellowstone last year in our 21 foot RV in 5 days and did not see everything we would have liked to see. Even our relatively short van was too large for some of the senic side trips which were restricted to cars only.