For those of us in the Northeast power outages are usually caused by snow or ICE storms.

Once went a week with no power, no heat, but we did have water.  

We have always installed, or have had installed, gas water heaters as well.  This way, you can at least take a hot shower from time to time to thaw out.

Last ice storm I covered my tanks with blankets and quilts, and would change out some water a couple of times a day to keep the temp and oxygen level up.  Cut WAY back on their food and let them forage to keep the tank from "going south".

Make sure your propane tank is full for your gas grill, cook food as it defrosts in the freezer.
Keep a kerosene heater working and at the ready with extra kerosene on hand.

Use the snow pile outside for the refrigerator,
and back at that time, keep plenty of "Blues" on ice.  Hey, when they close the roads you can't go to work, right?

Make pretend your camping and invite over those less fortunate, (yet more pungent, they will never forget this kind sevice).  You make lots of friends during this time.

Oh, one last thing, be sure Mother-in-Law is safely tucked away, SOMEWHERE ELSE!!!