Some 450 miles east of Château Cheval Blanc, the Saint-Émilion producer of one of France’s most celebrated wines, is Bernard Arnault’s other Cheval Blanc. Arnault, chairman of LVMH and France’s richest citizen, opened the latter property—a 34-room ski-in/ski-out chalet—in 2006 as his mountaintop palace, a winter retreat in his favorite …