Buy a Diesel and store Diesel.
That's fine for a single vehicle and I do that, but for the poster that may not be a practical solution.
I also have a need for gas storage so my solution was to build a concrete block structure for gas can storage, vented and covered in dirt 18" deep.
Welded up a door frame and 1/4 steel plate for a door.
All stuff I had around the place.
That gives me gas for generators, the 4wheeler, the wife's car, and the tractor,etc..
Additionally, no vehicle or piece of equipment is ever allowed to get more than 1/4 tank lower than full...we probably have 300 gallons of gas on the place as I write this and 350 gallons of diesel.
I'll be putting in an underground storage for gas later this year, but the problem is still stabilization...I use Sta-bil(tm) and rotate gas out every 6-9months...never had a problem.
To the OP, if you're looking to store gas for a getaway to a safer place, the gas cans are enough, just rotate the fuel...if you're going to stay in place and defend, it's a different story...