Off grid living in a town or city like the rural areas would be very expensive to set up in the first place.
I believe a partial answer is to go and live 'within the grid modestly', look around our homes and reduce the waste of power/energy etc. Its a lot easier to turn of appliances rather than leave them on standby etc than to go off grid, use low energy lighting, pressure cookers, cook the most economic way, insulate your loft, close doors, use heavy curtains even with double glazed windows, turn your heating down a couple of degrees and wear a jumper, little things like this if adopted by the population would make a massive difference. I'm using low energy bulbs throughout the house now, a simple thing but even that is saving perhaps 5Kw over 24 hours; multiply that alone over say 10 million homes and see how much it would save?