Joe,
My understanding is that they closely monitor any Canadians who return home - both CBSA/RCMP, and local law enforcement are now getting involved. It would be extremely foolish to NOT isolate upon your return, and get caught, because the penalties under the Quarantine Act are onerous, to say the least.
It's not just telling the CBSA border agent, "I promise to self isolate" any more. They actively check up on you. I also believe you're required to present your plan at the border when you re-enter, or they'll give you one, and the terms are quite strict and you will be monitored and the law enforced, if necessary. Stock up on food and other necesssities before you cross back into Canada, would be good advice.
So, you're right, it's not a game, it's serious, but it is doable.
Some info describing the requirements...
https://www.canada.ca/en/public-health/services/publications/diseases-conditions/2019-novel-coronavirus-information-sheet.htmlAnd the checking up process...as of May, and I doubt that they're relaxing the compliance checking.
https://www.ctvnews.ca/health/coronavirus/police-have-checked-in-on-nearly-2-200-quarantining-travellers-at-home-1.4949021If you like irony, truckers and healthcare workers, and other "essential border traffic" are treated much more loosey goosey than the rest of us. If a serious outbreak were to happen, it would more likely be from them than us, but so far, it hasn't happened, in either case.
