I've always heard long term gas storage (over a few months) even with stabilizer leads to gunking and you should pour old gas into your car tank when it's mostly full of fresh gas, so the mixture is mostly fresh gas. I also thought metal gas cans had fallen out of favor due to higher chances of rust and sparking. They were common some decades ago but all I see is red plastic now.

My current car is a Civic hatchback, 10.6 gallon tank at about 37 mpg (assuming not stuck in a traffic clog), so 350+ miles safe range. The hybrid Hondas use the same size tank with the Insight (2 seater) getting something like 70 mpg, so 700+ miles of range. I'll seriously consider that issue next time I go car shopping (not anytime soon). That approach seems in some ways more effective than trying to stash large quantities of gas to run a guzzling vehicle. At minimum, if I had four 5-gal cans at home, I'd rotate them--pour one in the car every so often and refill it. With a Honda Insight and a full tank plus 20 gal in the trunk, you're set for 2000+ miles, enough to get way far away from an affected region.

Frankly in a bugout situation I might well prefer a motorcycle to a car. Much longer fuel range than most cars, and can zip around traffic clogs.