I have read some articles/watched some youtube videos on dressing for the cold in the outdoors. Obviously there are varying degrees of cold from what we get in the UK hovering somewhere above zero to being in -20C in other places. I am a bit confused as all the suggestions are the same layering system - base layer, insulation, water/windproof. So how does what you're wearing differ at 5C, 0C, -10 and -50.

Do you wear more layers? Different types of layers? Or the same 3 but just better rated?