Another battery is just about the only thing that'll work. I presume you'll need a car to get up to this remote cabin? Maybe you could run some cables outside to provide for ease of jumping the generator with your car.
Years ago I worked a summer at a building that had a variety of generators in the basement. There were a couple of the very large diesel variety, but then there was also one pretty old-looking small four-cylinder gasoline powered one (which I guess was the back up to the back up) that had an electric start from a 12v battery (which was always on a trickle charger) but also a lawn-mower style pull-start. I asked the maintenance guy about it once, and he said that he had only tried starting it that way once and even that ancient low-compression engine was pretty tough to get started. I can't imagine it would be easy or even possible on a diesel, especially since if you've got a dead battery, you've got no glow plugs.