(The answer to my question is "No".)
But with every other car, you either get a few hours until you run your 12-volt battery dead, or you get 8-12 hours because you run the car until you run out of gas.
The Prius can operate as a generator. It’s computers can turn the engine on and off as needed to charge the traction batteries, which then feed this power function. As it said, at 1.5 kw full load, it can run for about 48 hours before it runs out of gas.
It isn’t the most efficient generator — a generator would be the most efficient generator. But if you already own the car, it’s a free emergency generator that can power your home’s essential functions in a power failure situation.