In reply to JoshOvki:
I stayed in Lledr House hostel last year. You would likely be in a dorm, has self catered kitchen etc. Within striking distance of Betws-y-Coed so you can pick up some fish and chips for supper on the way in.
No idea about snow, but it is directly off an A road.
Alternatively might Gwern Gof Uchaf bunkhouse be open at this time of year? Worth a ring:
http://www.tryfanwales.co.uk/
Post edited at 15:05