I had a 2007 Sightseer 30B which got 7.5 mpg. It was a wonderful RV which gave little to no problems. Handling was just fine. Once I parked it on frozen ground with several inches of snow. When I tried to move it would not budge, with one set of the duals spinning. I mention this since you said something about Alaska. With the engine up front, and without positive traction, this could be an issue if unaware.
It was traded in for a DP which gives a smoother quieter ride. This is sort of like always wanting a bigger telescope