Incredible boot, I bought it for everyday use in temperatures of -25 when I went to the northern region of Sweden, the Arctic Circle, and I never felt cold or humidity. I had no issues while hiking in deep snow and on uncleared paths, and they kept my feet very warm. The upper part at the top of the shoe, the fleece, is exposed, so if you don't wear good snow pants to cover it when it rains, water will gradually seep in from the top. In terms of size, I normally wear a 42.5 in athletic shoes, and I wanted the same size for these boots to have enough room in the front as these types of boots should have for wearing double socks, so I would say they are larger than expected. I believe they will be very warm for everyday use in Greece, but for snow, 100% recommended.