Based on that trailer, it looks like maybe they had a decent script doctor to figure out how to adapt this to make a halfway decent movie of it.

I was skeptical when I heard of this project and still am to some extent, but now I'll be willing to read some reviews. I don't expect it to resemble actual thru-hiking or even resemble any kind of backpacking I'm familiar with, but it might just resemble entertainment, which is about the best you can expect from Hollywood.