It would be a nice idea and I would suggest this to the BoC:
use polymer for 5 and 10 dollars notes and hybrid notes for higher denomination. Hybrid note is a combination of paper for most part of the note and a small part of polymer showing as a clear window. Many countries has already switched on hybrid note for their high denomination notes: Bulgaria, Samoa, Tonga, Kazakhstan, Fiji...
These notes are superb...
And incidentally: I hope that the BoC will not give us a fallacious reason for not using polymer as : "We don't have the technology" or worse: "These notes are too expensive for the BoC". It's no all the richest countries in the world that use polymer notes: Zambia, Bangladesh, Romania, Sri Lanka, Nigeria, Vietnam...