That was my thought, too. I don't expect an extreme situation will happen without a lot of warning; I'd expect financial problems first. A sudden panic could lead to the banks closing their doors temporarily until things cool down again, so it would be good to have enough cash in hand to coast for a week or two. If you can afford it: inflation is officially around 5% now so it costs to keep cash.

I am not expecting massive inflation in the UK. Nor in the Eurozone, really. Nor a Euro-breakup. Quite the reverse: a basic problem with the Euro is the diversity of member countries, and they seem to be trying to solve it by imposing more uniformity.