Bilboa to York (Should I shouldn't i?)

Right after a month off the road after my loosing my mate in an accident the idea of riding bike from Spain has popped into my head again.

Basically I want to know what the basics I need to cover are:

What to take as a minimum.
How long will it take to get back.

Has anyone on here done it beofore and are there any major pitfalls to avoid.

The plan in its most basic form involves travelling from Folkstone or Dover on a Ferry to Bilboa and coming back over the Pyranees through France. Stopping as and when.

I'd say you could get back from Bilboa to York in 3 days... but that would be all motorway. So the question is, how twisty do you want the route back to be!

Couple of years ago a friend and I rode from home (Bromley, SE London) to Torrevieja (near Alecante) in 5 days (taking a very indirect route), using roughly half motorways half twisty roads, averaging 350 miles a day, to give you an idea of what to expect.

Our bible was the http://www.hotelformule1.com/ book, listing all their clean, very cheap hotels. We had an idea where we were planning to stop for each night, but sometimes we over streched ourselves (and you most likely will too, so give yourself time and dont rush). When there are so many of those hotels there was always one nearby to stop for the night.

If I think of anything else I'll let you know.