As it seems we have missed answering the question: Keyser, the most likely situation is that CX will cancel the flights and auto-refund the miles to you. Following this you could ring up push hard and they may be willing to delay the tickets (i.e. let you fly in July say, which could keep changing for a while), but it sounds like that isn't viable for your family. As such, if very keen to travel around your dates the choices would be to take the QR flights and split up your family or choose to pay. If paying personally I would be choosing QR and booking now using cash, if miles aren't available:
1. QR's travel with confidence policy would let you cancel for free (if booked by the end of the month) if through some miracle CX did decide to fly so are a good backup
2. Their Qsuites are a great product, if you can afford business, if not they are just a nice airline
3. They continue to fly throughout the pandemic, so if they sell you a flight it will almost certainly happen (though probably +/- 2 hours based on my experience)
Good luck