British banks have quietly been reducing their exposure to a collapse of Spanish and Greek banks. Not sure spreading your money around is good advice. It just makes it more likely you will get hit. Particularly I would avoid moving any money to Barclays and HSBC with regard to expose to Greece. And Santandar would be vunerable to a Spanish crisis. But as we have seen before, no bank is safe. They may not be directly vunerable, but they may have investments in other banks that are vunerable.
The Nat West problem is slightly inconvenient for a lot of people but illustrates nothing. There every reason to believe that if the Government have to do another Northern Rock, that they will not hestitate to do so.
My advice to you is to fill your cupboards with food and lock yourself in doors for three months, all most of all, avoid the internet for at least 12 weeks.