For me it is all about keeping out the wind.
I prefer wind stop base layers that wick away moisture.
Cold feet can ruin a ride for me.
My favorite trick is to spray my feet with anti-perspirant, first layer of wool socks, next is wind proof socks, shoes with thermal insoles from hunting dept at sporting goods store. Over the shoes is booties of varied thicknesses dependent on wind/temp.
I am hoping to buy a pair of Sidi or Northwave winter shoes this year. Currently using a pair of Sidi's full Lorica that are 2 sizes larger than normal to accommodate insoles, socks, etc.