Over the years I've wheeled from the hills in california, deserts in arizona, nevada, utah, w. va, tn, pa, maine, etc etc, and I have never ever EVER had to bust out any of the jerry cans I always carried. Personally I've come to regard them more as weighty decoration rather than useful gear. At best I might carry a single can, and probably empty, as a place to maybe catch fuel in the unlikely event I rupture my fuel tank. Might. Maybe. Mileage of others may vary, and if I was contemplating retracing the Baja 1000 course or something I might reconsider, but for your general U.S. style "expedition" (if there really is such a thing in the U.S.) I find them more dead weight than anything.
In the 30+ yrs of wheeling I've done the most use they've ever served is to feed the generator in the stupid big 5th wheel that my city bread wife considers camping.
Not sure what I'm really saying here. Maybe a back-handed vote for the aux tank? ¯\_(ツ)_/¯
