Let me clarify what I am doing and why.
I intend to get a PCR test two weeks before my next trip in late October in hopes it comes back positive. That is because a positive PCR test exempts you from random arrival testing from 10 to 180 days after the test was administered. I have two more trips planned to Canada planned after the November one and it would be nice to have another "Golden Ticket" positive PCR test so as not to have to worry about arrival testing for any of them.
Hopefully, my county health department is still offering free PCR testing by then.
If the PCR test turns out negative, I intend to take one of my free home antigen tests just before I go so I can be reasonably certain that, if I am selected for random arrival testing, it will be negative.
If you just want to check if you are negative before you go in case you are selected for testing, there is no need to go to the trouble and possible expense of a PCR test. A free self administered antigen test would do fine, since Canada is no longer requiring a pre-arrival PCR test within 72 hours as they did until March.
As to deciding to wait it out until Canada drops its random arrival testing, that is perfectly reasonable. The possibility of a positive arrival test and quarantine is a pretty big risk factor for upsetting travel plans. However, personally, I like the VIA's Canadian and skiing in BC too much to forgo Canada now that the border is open. But I plan to mitigate the risk as best I can.