Apologies for the delayed reply.
I think it depends how you want to expose.
In low light situations, similar to the ones you describe, I find that at least a part of the subject is usually decently well lit. In the example of camping headlights a nearby subject (person, tree, what-have-you) would be illuminated - you can expose fairly normally for it, but everything else (background, distant subjects) will fall off into shadow. And the shadow area will be nicely controlled, not noisy. That looks nice to me on video.
The problems come when people want to 'see in the dark', and treat a night time scene a little more like a daytime scene. If you raise distant subjects or background info up, either using exposure or in post, you can run into problems with noise and unnatural colours. Also, to me, the whole scene starts to look 'off' as the viewers mind starts to reject the unnatural light levels being portrayed.
If you want the former exposure effect, rather than the latter, I think the C70 is the better option. If you want the latter effect then the C80 is definitely going to win.
Funny enough it was head torch only footage that sold me on the C70 in the first place.