I used Performance neoprene shoe covers for many years which got pretty ratty, and they were also not super warm. Recently I got some Castelli Estremo shoe covers, they are rated down to 15F and are a big improvement over my neoprene covers. Along with working great they appear to be much more durable. I have MTB shoes with cleats and they are not hard to put over once you get used to it. These are working well enough and I have few enough days a year when it is below 40F that I see no boots in my future..