Given Russia and China will most likely at some point hit the UK and US with cyber attacks (the new nukes) that will shut down water, sewer, power, heating, communications and the lot...what are your contingency plans?
My family has a refuge plan to all come here to our rural place and make like survivalists! I'd bet city dwellers would be screwed.
Guns, gold, cows, pigs, chickens, solar power, three wood stoves and a 500 gallons of gas...all set!
Something to think about anyway. Imagine the chaos and suffering in the concrete jungles if such a scenario were to take place. I might prefer to be ground zero of a nuke than try to make it in a dystopian cityscape.