In reply to SuperstarDJ:
Put my crystal ball down somewhere, can't recall where. ;oD
Seriously though, so much depends on the details of the weather. If there's some sun and you can get out of the wind you may be lucky. I'd recommend the Moelwyn crags as they face south and give shelter from N winds. Just to keep you optimistic - I've climbed there in tee-shirt in February! Air temp was just above freezing but the sunshine was unbroken.
The weather is usually better there anyway than elsewhere in Snowdonia and the rock is very rough and lots of routes will go even if wet. Some of the best routes at the grade you're looking for.
Good luck.