"Mr. Trudeau was forced by Canada’s system to abandon unilateral constitutional patriation and accept the “notwithstanding clause” override to his Charter of Rights and Freedoms."
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Trudeau backing off on unilateral patriation had nothing to do with FPTP.  Under FPTP, the majority of seats with a minority of votes allowed Trudeau full power to act unilaterally. Trudeau even  invoked closure in the House. 

It was a Supreme Court challenge and decision that ruled unilateral patriation legal, but a contravention of convention (as well as a little intervention from the UK). It was provincial premiers who represented the opposition force and who ultimately negotiated the consensus. The House of Commons was just a by-stander on such an important issue.

Talk about re-writing history to make a pre-determined point.