One night a few weeks from now, the stars will align and three productions of Pucinni’s “La Boheme” will take to the boards in New York City. That’s “more than 8200 seats to unload on a quiet, midweek evening” on Broadway, at the Metropolitan Oper and at New York City Opera. “Are that many New Yorkers going to be up for an evening of fake snow and chilly, Parisian garrets after five months of their own winter nastiness?”