[KozmoNau7]

As others have already suggested, wool is king.

I would recommend having a look at https://varusteleka.com, they're the biggest outdoor/surplus store in Europe, and they ship just about anywhere. Their wool flannel shirts and field shirts are the best I've ever owned, as are their worker wool pants, and they have enough merino clothing to layer for any weather.

Aside from the own brands, they often get very good surplus winter gear in, like thick Swiss knitted wool sweaters, Czech parkas, Finnish wool pants and so on.

My current winter outerwear workhorses are a Czech parka and a pair of Finnish M65 wool pants, total cost less than €50. With long johns and a woolen sweater underneath, I have yet to encounter winter weather that would make me uncomfortable.