Fourteen years ago, we moved ourselves from Rochester, NY to Orlando, FL. We rented a Ryder truck and my DH towed our one minivan on the back. I followed with the other minivan, filled to the gills with stuff and our then 3yr old DD.
So, even though we didn't exactly tow a trailer on the back of a car, I can emphasize that you just have to take it SLOW (we never really did over 45 MPH) and hope for good weather. We also had to plan our overnights at hotels to somewhere where my DH could just pull in and pull out so as not to have to back up at all.
We hit a DRIVING thunderstorm when we got to Jacksonviille, FL -- I will never forget it. We had a CB radio between us and I couldn't even SEE the yellow Ryder truck in front of me! I was so worried I lost my DH! But we made it and now live in Tampa Bay area and never looked back!
Good luck! VAL