I have a large Ergo in turquoise and I would use it in the winter. I am a "strappin' lass" and the handles fit nicely over my shoulder right now but I am not sure how it would fit with a bulky coat. I guess it depends on the coat. HTH
I probably won't use mine in the winter because of how soft and the buttery the leather is (plus because of the open top). I'm a little more "rough" with my bags in the winter so I want something that I don't have to worry about (stuff falling out, fitting over my coat, etc.).