How to get from Brisbane to Sydney right now given cyclone Alfred is causing delays/cancellations?

Basically as the title states. I have two relatives who are meant to be flying from Brisbane to Sydney today for their international flight to the United States tomorrow morning. Given the cyclone situation along the south east coast of Queensland all flights are delayed and public transport isn’t running. I looked to see if there were any trains (XRT) and busses (greyhound) had any options but there weren’t any.

Any other way for them to get to Sydney during this time?

Thanks