LifeMed Alaska offers a membership service to cover remote medical flights and the like. I don't know the membership restrictions precisely enough to know if its suitable for the OP's plan, but many remote lodges either provide or recommend that their summer help gets a membership.
The one time I was flying and stopped flying before I wanted to...and at a location I didn't want to stop at..I was picked up by the Air Guard and didn't have to pay a dime. Nearly 30 years ago, though. Conversely, had a colleague experience severe illness in the back of beyond a month or so ago and was told that his evacuation flight, had it not been part of his LifeMed membership, would have cost circa $40,000.
All that being said, I'm not sure how an "emergency evacuation" would play out on the road system.....not that it couldn't happen, just not quite the same as being off the road system.