While I agree with your remark about the NDP and the CPC being the parties of principle and the LPC being the party of opportunism, I also agree with Martin's analysis of how the NDP lost the election and why they should not now get "middle aged crazy" as they enter their late 50s as a party by going wildly to the left.

Even after the 2015 disappointment, the NDP still got the 2nd highest level of seats and popular vote in its history and substantially more seats and votes than the Liberals in 2011 when they finished a more distant 3rd.

The NDP's irrational overreaction to the 2015 results at their 2016 convention when they dumped their most skilled and effective leader and compounded this with surprising support of the (Look Before You) Leap manifesto suggest they will do worse in 2019 than in 2015.

But if enough millennials ditch the Liberals and return to the NDP, and if the party avoids a scary leader and a blow the rent platform, they have a shot at 2nd behind the CPC or LPC.