I'd think having your 'emergency fuel source' on hand where you live would be an important consideration, e.g.: a wood-burning stove or fireplace and a few cords of firewood, a propane heater and a large propane tank or two, a kerosene heater and a barrel of kerosene, etc. I think electricity is a poor choice to rely on in an emergency since it is so easily disrupted.
That being said, a lot of people simply don't have a choice in the matter. Apartment dwellers or someone who's home is powered exclusively by electricity are two such examples. People who live in apartments are bound by their lease and the law as to what is allowed in their apartment, such as space heaters, and the space to store fuel to power such devices. Also, since electricity is so easy to lose, quite a few people (who's home is mostly electrical) are going the generator route. My city allows a maximum of two 5-gallon containers of gas to be stored. That isn't going to last very long in a generator. So, your choices are obey the law and go dark in 3-4 days or ignore the law and store a larger amount of fuel, something incredibly dangerous, at least in the case of gasoline, and something many people will still do!
I can pretty much guarantee that if, for whatever reason, your local firefighters have to show up at your house and find two or three 55-gallon drums of gasoline in an attached garage, they're not going to be happy, nor will your insurance agent.