Roads within Yellowstone okay for towing travel trailer

I would recommend you enter YNP through West Yellowstone, MT and cross the center of the park to reach Fishing Bridge. As stated I would avoid Dunraven Pass. All of the Grand Loop Road is doable, some areas just better than others. Pull outs are available in the park. They are of all different sizes. Some paved some not. With only two days you will be busy trying to get it all in. But using your tow vehicle you should be able to hit the high spots.