In reply to Jackob:
The prerequisite for all this is you ideally need several days freeze followed by snowfall for anything in the Lakes to be worth a look. You can get good conditions if snow and freezing weather arrive at the same time, but it will take longer, (up to a week in my experience,) and benefits from at least one slight thaw.
Often the routes at the crags from the top of the Band over to Bowfell Buttress have something going on if anywhere does. There are lots of different crag aspects and both snowed rock routes and more traditional mixed routes to go at so early and semi early season conditions are catered for. We managed BB itself last season in good condition in what was otherwise a write off winter.
Gable Crag is similarly catered for, but has some more icy mixed stuff (Summertime Blues as an example) if the buttresses are not white enough for the Engineer Slabs style snowed up rock.
Ramps Ghyll Head is considerably further East than a lot of Lakes crags so can come in more quickly with the correct wind direction that the more popular venues further West - we found good conditions here in the 17 - 18 winter when climbers on Gable were reporting unfrozen turf.
Scafell can be very good but to be really hoared up it needs damp air onto cold rock. If you suspect that this might have happened then don't be put off by the valley feeling relatively mild, go and have a look.
Lastly the little buttresses on Dollywagon Pike, but be sure it is properly frozen.
Routes on these crags that I would say meet your needs that I've (mostly) done as follows. (I've put my own grade in brackets following if I think the grade is different to the one in the guide book.)
Scafell:
Botterill Slab V 6 (VI 7, but we did it as snowed rock without the ice down the corner)
Moss Ghyll IV 5 (IV 6)
Pisgah Buttress V 6 (VI 6)
Gable:
Summertime Blues V 6
Engineer Slab VI 7 (I haven't actually done it yet, but its reprted to be excellent)
Ramps Ghyll Head:
South Pinnacle Ridge IV 6
North Gully IV 5
Heirloom Crag:
Heirloom VI 6 (V 6)
Scrubby Crag:
Juniper Groove V 6 (VI 6)
Dollywaggon North:
Thrash Corner IV 5
Rescue Groove IV 4
St Sunday's:
Slab Route Buttress IV 6 (needs a bit of freeze / thaw snow)
Bowfell area:
Bowfell Buttress V 6
Bowstring VI 6
Plaque Route IV 4
Professor Rib V 5 (V 6)
Rib and Groove V 6 (V 7)
Post edited at 14:09