Can you survive with just a multi-tool and your mind?

Probably. Although depending on the terrain/weather, you could be pretty well miserable a lot of the time.

Could I survive with just my wits. More than likely, but again, depending on terrain/weather, I will not be really happy.

Would I do a Bear and try and find my way out? NO, unless I was sure of civilization being in reasonable walking distance. I mean I have a reliable map, I know the area, and damn near can see where I want to be, in good weather.

Would I do a Les and hunker down, find what I can, make what I can, do what I can... yeah, 90%.