Which plants do you have? My 75g was running with high lights, injected CO2, and an overstock of fish when hurricane Ike knocked out the power for almost 2 weeks. To keep the tank aerated, I added battery powered bubblers and performed frequent water changes. When the power came back on, I had lost either 1 or 2 fish (out of maybe 50?) and a couple of plants (remember, they required high light and CO2). The main difference is that my plants were already established.
If you have plants that need high light, then it might be best to float them where they can get natural light. If they're low light plants, such as anubias, you can leave them were they are.
If your power outage goes on for an extended time, such as 2 weeks, then you may need to bring even low light plants somewhere that they can get bright shade. Just remember to keep the water moving… if not by battery powered bubbles, then by water changes or even scooping up the water and dropping back into the bucket like a waterfall. Do not allow a film to form on the top of the water.
