If there is a true SHTF type disaster, distance is indeed your best bet if you can manage it safely.

The problem is that it is difficult to know whether to go or not because there is just no way to know whether whatever warnings are being given by the authorities are meaningful.

At some point getting the heck out becomes dangerous in itself and it might be best to just hunker down.

I know that is not really an answer, but most of these kind of hypothetical questions don't have a real answer because the answer is highly dependent on circumstances that are unknown, and are often unknown when the decision to leave or stay has to be made.