In reply to mburrows:
> Do I realistically need to get to Scotland then?
Realistically yes, you need to be looking at Scotland. In many years of winter climbing I've had one occasion when winter climbing in South Wales happened in November on two consecutive days, and although South Wales is even more fickle than North, I'd say it's just as unlikely, I really wouldn't even bother thinking it'll happen. If the stars align, you have time off work and a partner, do it. And even then, having done lots elsewhere since, I'll venture that it was all a bit rubbish. Otherwise plan for Scotland.
In terms of Scotland, plan for lean mixed climbing in the Eastern Highlands, most likely Aviemore. That's your most reasonable proposition as you don't need masses of snow, just cold temps followed by a bit of the white stuff. The cold temps are essential though to ensure that the ground is frozen hard as otherwise crampons and axes will damage the fragile ecosystem beneath the snow. A sudden cold snap with a dump is not good enough, it needs to be sub zero for days before hand.
All in all, I'd say you making hard and fast plans this far in advance is optimistic at best. IMO it's much better to keep some weekends clear and have everything ready to go so that when the call comes in, you go for it. Get into the corrie, assess the situation and see what's in, don't go out with the mindset that you ARE going to climb a particular route, or even that you ARE going to climb...
Post edited at 11:16