Surviving a blackout
We just recently got power back after living without electricity for 13 days as a result of Hurricane Sandy.  It was uncomfortable and inconvenient, but it was doable.  Here are some ways we covered the essentials: 
  1. Heat.  Space heaters hooked up to a generator can only do so much, both because they don't produce a lot of heat, and also because generators use gasoline inefficiently, which became an issue when everyone and their mother tried to power their homes with generators and subsequently created a state-wide gas shortage (the storm also disrupted processing plants and supply lines, which didn't help).  A propane-fueled space heater came in handy, but the real solution is to have a completely non-electric heat source such as a wood stove.  Too many other heating systems either still require an easily-disrupted fuel supply like natural gas or require electricity to regulate their fuel source.  A wood stove is the clear winner.
  2. Water.  Our well pump is powered by electricity, so once we used up the water in the pipes, we needed a backup source.  Our hot water heater is also electric, so showers were essentially out of the question.  Our water needs consisted of drinking, light cooking, light washing, and flushing toilets.  You can only let it mellow for so long.  The solution is to be a water scavenger, filling up bottles and jugs wherever you go.  We would fill up at work, at stores, and people's houses.  There's plenty of water to go around; it's really more of a logistics issue.
  3. Food.  Our outdoor propane grill really saved the day.  You can fry things on cast iron cookware, boil water in pots, and warm up leftovers on foil.  The other tool with a million uses was a Jetboil, which is simply a small metal stove that quickly boils water.  This coupled with a French press coffee maker made life worth living.
  4. Sleep.  Things got interesting the night I realized I could see my breath while sitting on the couch.  But a nice heavy down-alternative comforter on our bed kept us warm, even when our house got down into the 40s.  And even for Wendy, who's endothermic existence suggests she has no internal heat source.  I don't have any solid data for this, but I might've actually slept better than normal in the cold and without electricity.  Something to do with biorhythms perhaps.
  5. Electricity.  Our generator produced plenty of electricity, but we didn't run it for more than a few hours per day.  So to charge up our electronics and whatnot, we brought charger cables everywhere and charged our phones in the car while we drove places.
  6. Comfort.  This is something that's easy to overlook when it's difficult to get your primary needs met.  But in my limited experience, I've found that small things can go a long way to bringing comfort to an otherwise uncomfortable experience.  This consisted of a variety of things, from taking a shower at the gym, to cooking steak on the grill accompanied by a big glass of wine, to having a big cup of dark coffee in the morning.
It wasn't at all fun to live without power for so long, but it was made bearable by workplaces that were warm and electrified, local schools and businesses that provided showers, and friends that provided warm meals and the NFL Network.

Hierarchy of modern conveniences
Living without electricity, heat, and running water for a little while has taught me that there's a hierarchy of modern conveniences:  (1) heat, (2) plumbing, (3) hot water, (4) electricity.  This list is decidedly winter-centric, since that's when we tend to lose power, and also because winter can kill you, while summer can really only kill you if you're old.

Electricity is nice, but sitting in a cold house with the lights on (assuming you're unable to heat with electricity) is uncomfortable or unbearable.  Plumbing is nice, but if you can't take a hot shower, it's inconvenient.  At least if you have heat, you can sit around in a warm house, use bottled water to flush your toilets and wash your hands, and use flashlights to read books or watch movies on battery-powered devices.  In a cold environment, I can live with just heat; I doubt I could live with just plumbing, or just electricity (though typically if you have electricity you can have all the rest).