Depends on ambient temperature where your incubator is. If the core temperature of the eggs didn't drop below 96, you're probably ok. If the incubator is outside and the ambient temperature was cold, then the core temperature of those eggs probably dropped below 96. If the incubator is inside your house, or in an insulated, heated building, then you could be fine.
What was the temperature in the incubator when the power came back on? Do you know how low it got inside the incubator?
And what day of incubation was it on?