For towing high walled RVs, most people run into a tow weight well under the manufacturer's rating. Your Explorer has a lot of power, so 5000 pounds loaded good, even a high waled RV. Wheelbase is fine for RVs in this weight range. Looking through the
2017 Explorer Towing Guide as an example, I noticed a 500 pounds receiver weight limit and 40sq ft frontal area as being likely limits for you. That's closer to 4000 pounds loaded and a popup or Hi/Low type of RV is you strictly follow's Ford's ratings. You will have to decide if and by how much you are willing to exceed those recommendations. The 3.5L Ecoboost is used in the F-150 with over double the tow rating, so power is there. Cooling capacity I expect will be the most critical. Turbos and transmission will create a lot of heat when towing anything high walled.