1 month before I will board my expensive across-the-globe flight (US$1,000), she proposed an open relationship, reason being that I don't make enough time for her and if, only when it is convenient to me. We haven't talked for a week now, but I offered her to talk to me whenever she is ready.
It is three weeks until I fly to visit her, but if she doesn't reply, it seems that I will just chill by myself in fucking Hong Kong. I believe the timing is really fucked up. What do you guys think?
She's not wanting an open relationship. She's 'protesting' a desire to spend more time together, and the open relationship suggestion is being used out of desperation to have her need met. Some empathy may get you in the ballpark of preventing a rift, some re-assurance that you'll make effort to remain in contact during your trip may also help alleviate her fears.
Her behaviour exhibits a fear of a loss of attachment (most likely). If the relationship is important enough to you, learn to hear the need beneath her words and you'll be in a far better position to use these opportunities to grow closer rather than apart.