[Z-man]

Forgot about one thing with the battery trick - car batteries are DC, not AC.

So...
Find a fellow with a large SUV that has a DC to AC inverter built into the truck. Plug an extension chord into the AC power outlet in the truck. Now carefully take the wires from the house switch that powers your garage and slice them into the extension chord.

Now, you should have sufficient power to raise the door.

Of course, by now, I'm hoping that you have power back!

-Z-man.