Well, I didn't agree to the change back then because I thought I might find a direct flight as the departure day drew near. But that was risky given peak season, so I included a day in HK in itinerary and planned everything else accordingly. #3 is not an option for us, as I mentioned, one of us is already confirmed to stay in HK for one night. Hopefully we can reach #1...but if their no international stopover rule applies to an involuntary change like this, I'm out of luck.