Worth noting that some battery storage for your generator and a relatively simple controller would smooth it out pretty well too, and let you use your prius as a car during emergencies, and generally allow you to use a smaller generator if your loads a peaky (and allow solar/wind input as a potential contributor)
Hard for me to get excited about something so specific to one vehicle, since there are plenty of vehicle specific forums. Out of thousands of vehicles in the EM garage, 54 of them are priuses.
Also hard to get excited about it when it is solely for emergencies, if you are having enough emergencies that this would make a significant difference in the cost/quality of life then you might want to do some re-evaluating
