Having flown in from Hong Kong, the only direct flight option was on Cathay with the CX233/234 service. I was booked on J class for both legs, but with around 100,000 CXAM miles to kill I tried for an upgrade with miles online. Upgrading from Business to First on HKG-MXP v.v would cost 50,000 miles per leg, but it came to my attention soon after that the premium cabins were often full on this route. My agent suggested me to try again at check in on the day as it is common for CX to release seats at the very last minute. I ran out of luck on the outbound, so I kept my fingers crossed and hoped to be second time lucky.