Technical > Home Improvement > Using Dry Ice for Cooling backup for refrigerator?

Fill 4-5 1-gal jugs of water and put in freezer. When the scheduled day comes move the frozen jugs in the refrigerator. Maybe leave 1 in the freezer part.
I prepared 7-8 when Irene hit last year, they lasted for 2 days.
It won't matter if you open the refrigerator few times, the thermal capacity of the stuff inside is orders of magnitude higher than the thermal capacity of all air inside.