Not in Ontario, but there is a list and map somewhere of Ontarian businesses that don't support the passport, including restaurants and at least one gym. It's not large, but if you live nearby it is an option. A couple of those businesses were punished by local governments. There may be more places that just won't make it public to prevent reprisal (like during prohibition).

I've also heard of someone showing their phone (without the pass) and they were accepted. You can always try that and see if they'll take you anyway. I believe the government said they're still in the informing stage (not enforcing) but that information might be too old. If you're having a hard time with that, and you're willing to travel, look up how vaccinated each region is. The less vaccinated ones might be more likely to ignore the pass.

If you want a theater, drive-ins may be an option. Not sure if they stop in fall.

You can also just invite friends over, or see if you can get a local group to split the costs to build a theater room or gym that everyone can use if anyone has the space. You'd be watching older movies (or streaming), but there's plenty of them and new stuff sucks.