Lisa, it depends on what the size of the charge line from your tow vehicle as to how well towing while on 12V works or does not & the age of your fridge
. If its a an older fridge
the 12V function takes a lot of power. Many have found that their tow vehicles can not keep up to the drain the fridge puts on the battery
. In other words you can arrive at destination with a very depleted or dead trailer battery
and a warm fridge. What ever you do, don't park someplace and leave the trailer attached with the 12v running on the fridge..... not only will your trailer battery
be dead so will your vehicles battery if you do not have the charge line on the vehicle set up to stop working when the vehicle is shut off - many vehicles do not have that feature.
Putting a frozen jug of water or a freezer pack in the fridge while underway and do not open the fridge while traveling works well. Have have traveled for some pretty long hot days using that approach. Works fine - just put the freezer packs right beside the most perishable items - milk, meat etc.