Ski resorts in Italy are famous for their landscape, for their small charming villages and, expecially in the Dolomites, for the stunning quality of hotels and restaurants. luckily there are some exceptions.
I only know a few apres ski bar in Dolomites area. The most famous are located in Corvara in Badia and in Canazei (Val di Fassa). There are a lot of people from the end of december to march. In the "far" east of Italy there are some little resorts (visit the promotur.org site) and the resorts are better known for their wild landscape not for the nightlife.
Livigno is a particular ski resort in the nord of Lombadia region, it is near Switzerland and in high season there are some nice apres ski.
I don't know the situation in Piedmont region of in Aosta.
Have a nice trip in our marvellous country, Fabio.