Something I've learned being on the mountain, when the wind kicks up, and the sun's gone down, go ahead an put a small battery operated lantern on the mantle, and turn it on. Low setting's fine. Makes adapting much easier when the lights go out. And they do go out up here more than you might imagine.
Update: Awakened before dawn. Power was out. Little lantern going strong, and made it much easier to recover my glasses and a flashlight for a quick look around before going back to sleep. Power was off several hours, best I can tell.