The "perfect survival knive" many have found to be a mystical creature. Many have heard of one and hope that it really exists only to find out that what someone thought "did it all" was lacking in some way or another. Most of us have just broken down and continued to carry multiple knives that serve different purposes. I always carry my heavy duty knife for chopping and camp work, a medium knife for simple jobs and food prep, a SAK or multitool complete with saw, and a backup just in case. I've also added the CS Trailhawk to the lineup for gather firewood, trees and branches for shelter and hammering needs.
Many times, even I have thought that I found "the one that could do it all", but to be honest, I found that I would save a ton of time and effort by sacrificing a little weight in the pack and carrying more than one tool. I think you'll find this is the case too.