I am a cold sleeper and except in very hot and humid weather, my feet are often cold in my sleeping bag. If my second pair of wool hiking socks are dry I'll wear them in my bag, but when it's colder I like to augment my socks with Hot Socks from Integral Designs.
Hot Socks are lined with Primaloft. If your feet are sweaty or wet, they're great to slip into because the synthetic Primaloft fill will effectively vent the moisture. Down booties don't vent moisture well, and like down sleeping bags, become increasingly less effective in colder winter-like conditions. See my post on vapor barrier liners and clothing for a detailed explanation of the impact of moisture on down insulation in cold weather.
Drying your feet each night is one of the keys to blister prevention in winter and wet weather and these socks can help you keep your feet healthy in adverse conditions.
Hot Socks are not intended to be camp shoes and should really only be worn in a closed shelter or in your sleeping bag. They do have a reinforced Cordura footpad so you can probably wear them to pee outside at night, but I wouldn't wander far. They have an outer Pertex shell fabric that is water repellent and a soft back panel of Powerstretch fleece that makes them easy to slide on and off. They weigh a modest 4.8 oz.
Hot socks are not widely available but you can find them at ProliteGear.com for $44.95. That's where I got mine.
Disclosure: The author owns this product and purchased it using their own funds.