In reply to ADuck: The snow conditions vary massively but gully's and anything to the lea of east wind will be deeeeeeep
The Ramp and Idwal stream III but do ya self a favour and avoid the hords of numpties in Idwal.
My top tip would be Grugog Gully on Braich ty Du, Nant Francon massive route 600m lots of entertaining ice pitches around 3 some 4 but can be swerved. Head left once above the main difficulties and in the upper snow basin to avoid the deepest snow.
Another great venue is NE face of Foel Goch, Ogwen several top rate grade 3 adventures East Face Route, Curver and Yr Esgair and no crowds.
On Snowdon try Tregalen Couloir III accesed from the watkin path, consolidated and frozen due to being south facing, great route and hardly ever climbed.