having a gasser is more of a challenge (getting gas) than a DP...that can pull into a truck stop head-on and leave head-on.
What I do...around 1/2 tank, is to start checking. If a station looks good (does NOT have the pumps aimed at the store, rather parallel to the road) I immediately spot-check for what I call an "escape route". (How to get outta there easy). It can be a simple straight exit....or have to drive around the building...but that comes with experience....and it only takes ONE time...where one has to unhook the toad, back the toad up out of the way, back the motorhome up, hook the toad back up...in the rain..and continue on. That was me back in 2002. Once...was a great lesson. Yes..there has been some "tight" situations since, but no problems. My (our) "comfort zone" is 300 miles a day and that translates to just under 1/2 tank. I fill up before I pull in for the nite...so I can leave, of course, with a full tank. And...in a motorhome, pulling a toad...I don't look for cheaper gas. I need it...they got it...and 3-4 cents/gallon simply isn't (unlike a car) worth the bother or the time. Just get it.