To be honest, I think the closest equivalent of having 20 gallons of gas in jerry cans in the garage for an EV is having 20 gallons of gas in the garage with a large generator. I just don’t see how it’s possible to store the amount of electricity needed to power a EV that isn’t a huge setup. Gas certainly has a lot of power for such a small transportable package that can be refilled quickly which is why it’s been so popular. I’ve been holding off on even considering an EV because of things like number of charging stations but I had not even thought about how I would charge it during an emergency. Perhaps solar panels on the roof of your house could also work to power it during the day. I’ve looked into solar panel packages and was quoted $10,000 just for the panels and that didn’t include any batteries. For 10% of that I can store 20 gallons of gas and a large generator.