I think your babies will be fine. I had a power outage my first clutch on its 3rd day of incubation,
I had dips as worse as the how 70's and brief spikes up to 96(the water I added in the bator was too hot most likely)
That outage lasted for 2 days though I did manage to keep the temps stable most of the time, It was only when I needed sleep that I'd then wake up and find the bator temp in the 70's.
In the end all 9 of my eggs hatched fine, tho 1 baby does have a minor tail kink, I really don't think you have anything to worry about.