There are several things that you can do to help your tank through this. You can add warm water but be sure to warm the tank slowly. You don't want to put in boiling water, that will be worse than the temp dropping too low. If you have any heavy blankets, toss them over the tank. These will help keep your tank from loosing too much heat just be sure that they aren't actually touching the water because they will start to soak up the water. If you can get some foam sheets (the blue ones that they insulate homes with) place them around the perimeter of glass or acrylic. This will also insulate the tank. For oxigination, i would hit up your LFS and see if they have any battery powered power heads. If not then stirring should be fine. If you can afford it, you can look into getting a really small generator. Just be sure that you have enough extension cords to reach from outside to the tank. You don't want to be running the generator inside your house.
I don't think that boiling the water before putting it in the tank is really doing much, other than possibly killing any living organisms in the water. The chlorine and chlorimine will still be in the water, so I would be inclined to suggest to just warm the water on your stove to around 82°F (then add salt and a water conditioner as needed). Good luck and hopefully you won't loose much in the process.
