Plus, there are backup-power lories and refrigerated trailers. If your shop doesn't have enough backup power for duration, you might see several of these pull into the carpark all at once. If not all of the chillers can be powered, shop's staff will schlep stuff to the refrigerated lories.

Seen it done in USA, for a Target next to a Kroger grocer. Kroger lost everything that needed cold after reserve either ran out or wouldn't start, but Target had a contingencies contract and lost no product.