I've towed my 2008 Liberty 4x4 auto trans thousands of miles behind my motor home, 4-wheels-down (no dolly), no problem. This capability is a feature of this and some other Jeep models.
The vehicle manual explains how to put the trans in true neutral (via tiny button on shifter plate). But I believe this is only possible with 4x4 and certain auto trans.
When I first started, I also called Jeep for confirmation. They were clueless about how the vehicle actually operates, all they could do was read verbatim the same manual page I told them I already read. And they understood not one word of my additional questions. Clueless.