Everything about this situation so far has resulted in the worst thing happening. Nothing has improved from day 1. Thinking of how the situation could further spiral out of control isn't scaremongering. It's called thinking outside the box, and planning accordingly.
Whilst I don't agree with everything Xeptu has said, they are bang on the money on more than a few points.
Have a good think about this 'out there idea'.
Whats the backup plan if internal borders stay closed? Business leaders will next push for the PM to hold an urgent referendum on a vote to become a republic. A president elect will then have the power to dissolve states, and the power states have over their own borders.
Yes votes in a referendum from NSW + VIC alone would out number No votes from WA + NT + SA + QLD + TAS.