westend wrote:
If you don't travel but a few miles, you could either invert 120V off the truck or make a dash for it before temps rose in the freezer. Using an insulative blanket or box would greatly aid in slowing heat transfer.
I studied insulating the "modern" chest freezers, and apparently it's not recommended. Rather than an external cooling fins, which become clogged over time with debris, the new units have the fins sealed into the walls of the unit, and radiate their heat through the skin. Insulating these walls would trap the heat, and cause the device to malfunction or operate with terrible efficiency.
Do you have first hand experience with a chest freezer thawing quickly without power? I've had my home upright freezer go nearly two days without power and nothing thawed out... it could have made it longer, but power was restored.