I have done a number of things in the sierra winters. As other have pointed out, it doesn't get as cold in the sierras as many places. I have tried a variety of things all of which worked.
Much of the time I have used a thin liner, sealskin waterproof socks, trail runners, and a light gaiter to keep the snow out of the shoes and the bottom of my pants.
When it's been consistantly below 20F (or there abouts) this combo doesn't work and I switch to something else. In colder weather I have used to three things:
liner, vapor barrier socks, moderately thin insulated sock (I think wool & thermalite... got them a long time ago), trail runners, and gaitor.
Light socks and some Baffin boots I picked up last year (don't remember model and they are put away in the garage). The baffin boots are just over 2lbs and are rated to -20C (-4F). My feet have been toasty with light socks down to 0F. Haven't used these boot below that yet.
liner, heavy wool sock, ancient vasque full leather boot (snowsealed), gaitor. These work for a couple of days, but eventually they soak through. Once that has happened I can't get them dry until I am back home. :-)