Can you go 3 weeks?

I was recently in a class and one of the other students made some shocking statements.  He was part of an exercise in a metro city. The exercise was designed to test the what would happen if the electricity  went down.

Long story – short, if a sub station went down it could be weeks before the electricity was back on.  Apparently conductors are now being made over seas.  Due to this the time to get a new one is 3 – 4 weeks.

Can you survive 3 weeks without electricity?