I'm a UK 10.5, but I can ring the place in Anglesey tomorrow, I was busy today.
How long are you in Wales for, if you're around into the first weekend of January I might wait till then to see if the weather improves. I'm mostly interested in getting some winter snow/ice experience than scrambling right now, but I'll see how things pan out, Grade III would be fun!
It depends on the weather really. If there isn't much snow, I'd really like to do the Bochlwyd Horseshoe. If it's proper winter conditions, probably something a bit easier. The Y Cribyn ridge looks like a fun ridge on the way up to Snowdon, could then double back and do the second half of the Snowdon Horseshoe