Cronk, I lost power for a week during hurricane Matthew (Oct. 2016). I was in around week 7 of flower; it was my first grow. I was told to remove most of the water from the reservoir so the roots wouldn't drown, and I opened the curtain during the day. When power came back on, I had a fantastic harvest a couple of weeks later. Where I live, the weather was still quite mild-- the temps were ok for the plants.
So I wouldn't worry about a brief power loss unless it's freezing outside! Give your girls what light you are able, explain the situation to them and assure them that the circumstances will return to normal very soon. This will help you all to feel less stressed--I don't know about you, but I was stressin too much when it happened, but that was cuz I didn't know any better yet. ;-}