Can I use the same bank statement for my spouse and myself when applying for a 90-day Non-O visa in Thailand?

Wise - definitely set up before coming to Thailand !!

We have a joint account in our home country. For application we just sent the statements from same account twice, showing balance of the last three months equivalent to 1,6 mio thb.

On Wise, set it up now while you’re still in Canada. Link it to your bank account(s), do a couple of test transfers, and make sure everything is working smoothly before you leave. That way, when you open your Thai bank account after arrival, you can transfer funds to it right there at the branch, sitting in front of the teller. The money should appear in seconds. No need to go back to your hotel, install the app, and hope for the best. Get it dialed in now, and it’s one less thing to worry about on your Thai banking day.

Is it a joint account? Your consulate might accept that but it will need at least double the money in it. If it's not a joint account I doubt it very much