Nice idea, but as voltages go up the protective equipment that one has to wear when working with them changes. Of course, if you don't mind wearing Class 2 or 3 Electrical PPE (rated rubber gloves (tested every 6 months) with leather overgloves, long sleeve fire retrardent shirt (11 cal/cu cm. I think), "E" rated hard hat with eye protection and face shield etc.) then you can cook up the voltage and hook up the cord.
In reality, when you go over 250 volts, things are a lot more dangerous. Putting 480V in the hands of the average motorist is like giving flares and black powder to teenagers; someone's going to get dead and that's a certainty.