We pulled a Toyota Sienna on a tow dolly for two years and it did not work out. The Toyota is very wide and even with a larger tow dolly, the dolly fenders would hit and damage the sides of the minivan on tight turns. About $1500 for fix the minivan once we got home.
Our in-laws have a Dodge Caravan that is much thinner and we could tow that with no problem.
After 10 years we gave up on the tow dolly all together and now pull a Jeep Grand Cherokee which pulls like a dream.
Tom and Katharine
'07 Winnebago Tour 40TD, 400hp Cummins
RVing for 19 years & 150,000+ miles