for large fuel storage of pre-mixed fuel, i use one gallon plastic bottles that are commonly used for windshield washer fluid. these are the same containers that model airplane fuel is sold in.
i use seafoam metal containers for smaller storage that fits into my bike bag.
you can also hang around a hobby shop and find someone who buys model truck/car fuel by the quart. these quart size bottles are perfect for needing fuel storage on the road.
warning; the plastic bottles are not vented so you should keep them out of direct sunlight or store in areas where they get heated. i have stored them in direct sun as a test with no issues but better safe than sorry.