Space for Life Passport vs individual tickets?

Bonjour! We (two adults) are in Montreal right now. It's lovely, but warmer than we expected

We want to go to the botanical gardens, but the website keeps sending us to the passport ticket site ($112 for two) for all the various spaces. It looks like a good deal, and you don't have to reserve a time.

Is that right? We are here for the week. Any other suggestions? Is there any place to SWIM, for example,? Tomorrow's going up to 90 degrees!

We have a car. But should we take the metro instead?,

Any info would be appreciated. The website is kind of confusing. Thanks!