That makes sense about splitting up.

Regarding a fire, even if you don't have fire for complete warmth through the night, you can still make a slow burning fire. Even a tiny flame the size of a candle would be a lot better than cold darkness for 9+ hours. I wake up every couple hours even in the nicest conditions. Out there, I would probably wake up every half hour or so. I could keep a slow burning fire going throughout the night.