It's amazing how few people have a corded phone any more. Many don't even know that there is such a thing as a line-powered phone. ...snip...
I always have 2-3 corded phones in the house, and so far, have not switched to things like FiOS so that I can have a POTS phone
I have a pair of Army field phones and wire to string out if I need them at a shelter for comms - I also have a Butt set in my go box, along with a linemans nut driver....