I have the same problem (as discussed in the other thread on this route you started) and you cannot link them (as in: liability for when snow hits the fan), not even as a Gold.

What you can do (but you need to be miles rich) is to book several rewards the days before. So, if the weather is fine you simply cancel them. If the weather is bad you depart one or two days earlier.

Another alternative I have contemplated is that (if the worst case scenario becomes reality) CX will allow me to fly AMS-HKG in F instead. CX has been brilliant in service recovery so far, even when it is someone else's fault. The seem to appreciate OW emerald status the most.