Thank you for all the replies! The scheduled power outage has been pushed back a week. I am most grateful that this has happened as it gives me more time to prepare. In retrospect, I should have been prepared for this, especially considering that I have thousands of dollars invested in the tank and it might just kill me to have to start over!
I have been collecting heavy duty extension cords so that I can attempt to run a line from a laboratory that is unaffected. I am told that labs 3 floors up will not be affected and I can simply run a cord down the outside of the building.
After reading all the posts, I am wondering if a deep tank can really go 8 hours without circulation. While it is true that livestock is shipped overnight to us, the surface air/water interface to volume ration is much higher in a bag compared to the situation in a tank. I would bet that the bottom of anyone's tank would deoxygenate very quickly due to the activity of corals, anemones, crabs, fish etc. While the fish might be able to escape this environment, by moving up in the water column the sessile livestock cannot. I for one am not willing to take any chances!
Finally, I am rather surprised that there are not devices that are sold specifically for this issue. It seems to me that a young entrepreneur could make a nice profit by designing a UPS specifically for the saltwater hobbyist that would kick in to at least keep pumps functioning in the event of a power failure.
Thanks again for all the discussion!