Daniel Hughes lived large, figuratively and literally. Now the former New York City-area union chieftain is facing a major downsizing in his lifestyle. Hughes, ex-president of Port Authority Field Supervisors Association Local 111-S, pleaded guilty in Brooklyn federal court on June 16 to embezzling nearly $300,000 from the union over the course of a half-decade to finance his seemingly boundless appetite for hookers, gambling and gourmet meals. The union, whose roughly 250 members perform roadwork at Port Authority-managed bridges, tunnels and airports, is for the time being out of money. Hughes is trying to deal with a bigger dilemma: a prison sentence of between 46 and 57 months.