I just ordered these from Kohls & I can't say they are the warmest since I haven't ventured in the snow with them, but they are soooo soft & cozy in my boots for the errand runs. They are also BOGO 1/2 off right now.
Ditto smart wool as well as wool bombas I really like both brands for warmth and fit. They come in multiple sizes vs mens and Womens.. See- smart wool See - bombas