You know, everyone could do what the Australian's Did and swithch to Polymer notes.
They would definitely have a longer lifespan
Seriously, back to the coins discussion, something similar happened in India, where they slowly stopped printing 5 rupee notes and minted coins insted.
So now, while you may occasionally run into an old fiver, the coin is the standard.
They're talking about issuing a Rs. 10 coin as well, as that is the not that currently gets the most circulation.