In reply to annak:
Having been to both Cogne and the Ecrins, I'd have strong reservations about early ice conditions in the latter, so much so that I wouldn't even consider it as a new year venue. I've been to the Ecrins several times in January and experienced very mixed conditions there in more recent years. The last time I went was in late Jan 2012 and it was very poor there then; very poor in La Grave too although Alpe d'huez and Ceillac were ok. Cogne and nearby valleys (eg Valsavarenche and Val di Rhemes) were in brilliant condition in late January of this year and Cascades de Lillaz, for instance, seems to have been in climbable condition in the first week in January in the last few years as do the routes at the top end of Valsavarenche. So of the two, my vote would be for Cogne over the new year.
I agree that Maltatal is another contender, but it's difficult to get reliable information about early season conditions there.
HTH
Dave