What a wonderful site! I wasn't expecting so many great replies!
I think I'm going to bring them inside into the conservatory. I was planning on doing this anyway but last year all my seedlings got damping off in my conservatory and so I was worried my Geraniums might suffer similar fungal problems this year. Still, I suppose watering sparingly might prevent this.
Going to bring them indoors and see if any of them can be salvage. Thankyou for your great replies,