Guests of billionaire Nets owner Mikhail Prokhorov had a smoking Russian Christmas, literally, in chic Courchevel this week. But luckily no one was hurt. Fire broke out at a boutique hotel in the French ski town, we’re told, where 150 guests — about 30 of whom were guests of Prokhorov during his annual Alpine getaway — had to be temporarily evacuated. A spy said many of those fleeing into the snow were “attractive 20-something girls.” A rep told us: “There was a fire affecting Mikhail’s guests [who included married couples as well as single men and women], but everyone is OK.” Back home, Prok’s Nets have been on fire with a 5-1 record since he tapped interim coach P.J. Carlesimo to take over.