Just to be sure I would do it at the battery, than we know it is a complete NO POWER situation. Let it stay unconnected for a few minutes, reconnect and give that a shot.
Another way to remove power from the fridge is to disconnect the power at the fridge controller if you know how to do that. I have also heard of ways to reset by shorting points on the control board, but I am not confident enough to do that without assistance. You can search on the web or call the Manu. and see what they say. Always safe to do that.
Try the battery first or if the battery has a fuse pull it. Easiest to try.
2013 Ford F-350 SD Diesel, 4X4, Crew Cab, Lariat
Sabre 2014 32RCTS, Pullrite Superglide 2900 18K