What is your temperature outside? Another case where knowing your location might come in handy. Is it reasonable to take them outside as well as insulate them?
How far along are they? Not turning them for 8 hours should not cause any issues but the later they are in incubation the more heat the eggs themselves generate. I'd be less concerned about the heat late in the incubation that early.
The UPS is a great suggestion. Do you have or can you borrow a generator? Can your incubator operate off of a direct current car or boat battery? I'm not sure what your options are.
As long as they are not real far along the option that will cause you the least concern is taking them to a friend as long as you can safely transport them. I'd probably pack them in cotton to protect against shaking as well as provide insulation.
Personally I'd probably insulate the incubator and take my chances. If I had room I might fill a hot water bottle with water around 100 Fahrenheit and put it in as a thermal mass to help maintain heat. Don't overheat it and cook the eggs.