There are several full hookup sites at Kodachrome -- and let me tell you, when the temperature at night dips to NINE degrees above zero (as it did on several nights when we were there in mid-November of 2014), it was great to have electricity. When it gets that cold, the batteries don't last nearly as long as they do in warm weather.
And in keeping with the "dark skies" theme of this thread, we brought an electric blanket, knowing we would have hookups. Using a long extension cord, we set up the electric blanket under a big sleeping bag, so that we could sit outside on our lounge chairs, covered with the blanket and the spread-out sleeping bag, and look at the stars. Very pleasant, despite the really cold weather!