This is pretty ahistorical. Most of the world's great civilizations have been from warmer climates. Northern Europe is an exception, not the norm.

All of the world's "great" civilizations come from places with strong seasonality. The ones that didn't have winters had flooding seasons and dry seasons. Some of them had both. It also doesn't need to be bitterly cold for winter to have an effect on crops.

Sumeria and Egypt both had seasonal flooding. Italy and Greece have winters that are cold enough to disrupt agriculture. The Aztecs and Mayans had seasonal floods. The ancient Chinese empires had both. Japan has winters. The list goes on.

On the other hand there’s something to be said for a comfortable climate that leaves people with time to think when the everyday isn’t a constant complex struggle.

The Inuits of Greenland and Sami people of Lapland didn’t have Aristotle or Confucius.

That is only due to writing. I always felt that the high latitude civilizations led to technological development due to the high risk and high solitude.

Maybe there's a "sweet spot". Too warm and not enough seasonality leads cultures to not be that productive, but too cold and daily life is just too much of a struggle to invent calculus. Greenland and Lapland are probably too far north to have decent agriculture, and never had large enough populations to develop much civilization. Cultures that had people like Aristotle or Confucius had very large populations for the time.

That we know of; did they have a system of writing?

I find it hard to believe they wouldn't philosophise at all. Confucius got famous (like sun tzu et al) because his ideas were written down, published and spread.

The number of different words they have for snow and ice demonstrates a cultural understand of distinct attributes of objects. I think this would be the first step of consciousness understand one thing as distinct and separate from another.