^ that person you're asking hasn't posted for four years. But to answer your question, these factors may help:
1. I've read of eggs being interrupted during incubation for 18 hours and having a normal hatch rate still.
2. Your incubator (and the room around it) should keep the eggs warm for a period of time.
3. From day 15 onward, the eggs start generating some heat on their own, so the amount of heat in the incubator isn't only coming from the incubator.
They may be a day late. Or, if they were going to hatch early, there still may be some delay and they'll hatch closer to on time rather than early.
You've probably entered lockdown but if you haven't I suggest candeling with a strong flashlight. Look for good clear veins and movement. If there is no movement, don't sweat it. I have had times where I swear I killed eggs from overheating, cooled them off, candled and thought they were dead. Then I put them back in the incubator and 12 hours later re candled and they were moving around like normal. In your case they might also be sluggish but you can candle before and after the twelve hours or simply start lockdown.
Some things that helps in the future:
Having incubator in most stable temp part of house. Cooler part during summer (unless you leave AC on) and warmer part during winter (unless you leave heater on.) a lot of incubators come with styrofoam packing. Use that packing below and above to help insulate the incubator and keep it at a steady temp, especially in case of outages.
If you only have a few eggs to incubate, keep a few dummy eggs in there as heat sinks. The more mass in an incubator that are brought up to 99* internal temp, the more the incubator temp stays steady in general, when dealing with hot/cold spots or power outages.
. Thanks for all your advice and making me feel better after the power cut! 
