In reply to chris fox:
As Chris mentioned, the various finishes to Central Gully on Great End are good, classic gullies. The classic lakes III/IV is Raven Crag Gully, which is as good as many Scottish classics. One solid week of proper freeze and it should be ok, but it is low down. Photos from this April give a misleading indication of the usual quantity of ice! Normally there is less.
Another classic III is Pendulum Ridge on Scrubby Crag, though I think it is as hard as your average IV in Scotland.
Little Gully on Pavey Ark is very good too but needs a reasonable freeze to bring it in. All the low level gills are good after 2 weeks freeze - whorneyside force, Cautley Spout and Launchy Gill are well worth it, as is Sourmilk Gill in Borrowdale.