I wear my Sidis year-round. When the temps drop under 50 I have some neoprene 10 y.o. toe covers. And when it's 40 degrees and less, I have a pair of neoprene, water and wind-proof Endure covers that come up well past my ankles. Those, and wool socks, do the trick. Louis Garneau also makes a similar neoprene bootie. I'm sure others do as well.