No matter how enclosed you feel in the Go-One, it is still important to wear a good base layer of clothing. I for one like to wear wool as a base layer. I read somewhere that there is a natural advantage to wool’s insulation qualities. The organic make-up of wool takes advantage of the insulating property of air. If you choose to shop for wool base layers, buy the good stuff. It is more silky and comfortable.
Oh yea! Also check out Lake Footware. They make a great cycling boot which can keep you feet warm in the harsh weather. They are also waterproof.