Ten hours -- without interruptions -- is probably workable if the pattern is as simple as you say. If you're traveling with small children, all bets are off though.
There are all manner of small battery operated lights that might do the job, but a lot of it will depend on the color of the yarn and how good your eyes are. If it's a dark color it might be hard to manage by flashlight. My girlfriend can knit by the map light, or even in the dark if the pattern is simple. But she does this for a living and has been knitting for over 30 years, so muscle memory takes over.
But the absolute worst thing that can happen is you don't get it completed on time, in which case you can give them what you have and finish it after all the festivities are over (or even while they're going on -- which I find can be a VERY useful distraction!).