You might be okay for a couple days (with no lights), but I like Irydyum's idea better. Just make sure to have (at least) a small ventilation fan kick on with the lights in case they might build up too much heat in the flower room.

You don't need a lot of power; tell your plants it's going to be a little overcast...

I'd probably use 6500K CFL's or tubes rather than the usual red flowering spectra--it's the blue light that tells your plants it's "daytime." You won't add any bud mass with them, but at least your photoperiod will stay on schedule.