I answered
Years
While not the same thing, I have done a 500 mile thru hike in the rockies, and I think I have enough survival skills to figure it out if the stakes were that high. I've definitely got the basics of fire starting, navigating, back country decision making, etc. And while I might not make it, I think I would have a better shot than a lot of other people and at bare minimum would panic less, which is key in survival.