This happened a few years ago on the way to SIN for us. Were on W fares, using SWU to fly in C. Rather than overnight in NRT (needed to get to SIN following evening for flight to HKT and didnt want to cut it close) we got confirmed in C to HKG on UA (flight still hadnt departed NRT) and overnighted at the airport hotel with first flight out to SIN on CX. Convinved UA staff in HKG to change CX flight from Y to C (wife was GS at the time). Was fantastic, CX in C was great and hotel in HKG had great dim sum brekkie.