I'm pretty sure I read this book. From your description of the film it certainly sounds like it. They were searching for a rumored "utopia" that was meant to exist at the top of the world I wanna say.
I never heard of this series and if it had not been for your write up I likely never would have... so thanks for that. This looks like something I could have on in the background while I am doing other things :)
you are welcome