instead of a whole gas can, you can carry a pint (or even half-pint) two-stroke container. i like to keep one handy.
once the two-stroke is gone, you can fill it up w/ premixed gas. a pint is about a quarter tank, which should be plenty to get you home. if you get at least 100mpg (as most peds do), then a pint should easily get you 20-25 miles. even a half-pint two-stroke container filled w/ premix fuel will get you about 10 miles or more. and it's smaller, so you can carry it much more readily (even in a coat pocket).
of course, topping off the tank every night helps, too. after all, since you have to premix, i just buy two gallons every month or so and premix it to take home (i carry it in a large army surplus backpack). top off the tank every night or so, and you've got no worries.