The necessary procedures for towing four down vary widely (and wildly), depending on the vehicle.
many years ago, I towed a 1963 Corvair. the recommended procedure was to stop every 250 miles and run the engine to ensure proper transmission lubrication.
then I towed a Jeep Wrangler. No limitations at all! Any speed, any distance, no battery discharge, no problems. Later models will discharge the battery while being towed.
the required procedures are VERY vehicle specific. All one can do is read the Owners Manual for the specific vehicle. All necessary instructions should be there.
If you already have a vehicle that can be towed on a dolly (not all vehicles can), there is no need to buy a new vehicle. Try it. you just might find that all the doomsayers and naysayers statements simply don't apply to YOU! I tow my PT Cruiser on a dolly occasionally, and I don't have anywhere near the trouble described by some of the naysayers and doomsayers.
Only YOU can decide what is right for YOU.
Good luck.
