Judging by the pic's it appears there's some sort of processing happening at their work camp. I'd guess mining. I'm certain they receive supplies and provisions during the fair weather months.
I never thought about the fuel situation, I'd bet diesel is readily available but premium would come at just that, a very premium price.
On that thought I think the best Cigarette boat to have there would be a diesel fired Cummins or Yanmar powerplant for longevity between services and minimum fuel consumption for distances traveled.