On turning back
The hardest skill on a hill is not endurance. It is turning back earlier than you want to.
In January the light goes fast and the temperature with it. I set a turnaround time before I start and I keep it even when the summit is right there. The hill will still be here next month. Twice this winter I turned back within sight of the top, and both times the walk down in worsening weather told me I had judged it right.