Lace scarf with silk/cashmere yarn? That is for in the vehicle. Lace scarf with sock yarn? At the campsite during the daytime. Sock? In the backpack for the beach or some other place we might go.
Some people are concerned about the dirt of a campsite, and I am cautious. I pack all my projects into their own plastic zipper baggies, with the pattern, needles and anything else I might need.
The campfire ... really that is perfect knitting time. But there is the issue of the smell of smoke and the potential for sparks. This is not the place for knitting a precious sweater or shawl.
The perfect campfire knitting is that most humble of projects - the dishcloth. I love knitting them at the fire, as I don't need too much light and I don't mind if they smell of smoke, after all they are made to get washed!
Another tip for campfire knitting: I use a headlamp around my neck if I'm doing a project that I might need to look at. I don't keep it on my head, as it can be rather blinding to the person I turn towards when talking.
Proof that I know whereof I speak:
Knitting at the fire at San Josef Campground (North Vancouver Island).