Inventive entrepreneurs are at your service:
Jason reminded me of something else, when towing with an RV. Except for diesal pushers, RV's are not designed for lots of tongue weight. Imagine going over a common "whoopteee" rail road crossing. The tongue weight goes from almost zero on the "whoo" then goes extremely high (like 5000 pounds) on the "teee". Couple that with the long over hang on many RV's and you create a lot of stress on the chassis. I actually broke a motor home chassis with a 24' enclosed trailer and a Miata. It can happen and is a real PITA to repair.