Dr_Midnite said:1. Do not attempt to travel back into Canada without your PR card, the COPR sheet stapled into your passport clearly states “not authorized for travel”. It applies to any commercial carrier entering Canada i.e. plane, boat or train.
2. I was advised to ensure I arrive in the USA and cross into Canada via car, the document will allow me to enter Canada via car. As I am a UK citizen an passport holder I am able to enter the USA without any restriction and then travel into Canada.
Whoever told you this is an idiot. As a visa-exempt British citizen, you can travel directly to Canada on a commercial carrier on just the strength of your passport as if you were merely a visitor. Remove the COPR from you passport and don't mention your PR status to airline staff. Once in Canada, you would then present yourself as a PR to immigration, who can confirm it by simply swiping your passport.