Gen 5 Block Heater

I understand an engine block heater is optional, but here in Canada, the dealers usually make it mandatory.
One nice thing I like about my Gen 5 Prius Prime is that it has an outside connector for a block heater cord, that detaches and stows in a compartment in the back. This solves two problems; you don't have to pinch the cord in the hood, or have to fish it through the grill. The first problem leads to the second problem; when the heater cord flaps in the slipstream, it eventually breaks the wires inside. I'd venture to say that a lot of people here have a broken block heater cord and don't even know it. They try to start their car in extreme cold, and it either starts, or they call for a tow, which usually result in the sale of a new battery. Sometimes a new block heater cord as well, which lasts until the wind-flapping beaks that one too.