I agree with RoyB. As a back up, carry a portable tank so you can park and walk to the pump if you can't pull up to it.
Also, if you have a diesel you can look at getting a replacement fuel tank with larger capacity so you can drive farther without having to fill up. I replaced my 28 gallon tank with a 50 gallon tank from Transfer Flow. Now, I can drive 450-500 miles with the fifth wheel in tow before I have to fill up. This allows me to put in 350-400 miles between campsites, drop the trailer and go fill up without having anything in tow.