For a seller, rates matter mainly through their effect on buyer demand. Higher rates shrink what a given buyer can qualify for under CMHC's stress test, which can soften how many offers a listing draws even when the sale price itself holds up.
For a buyer, a one percentage point move on a typical mortgage changes the monthly payment by a real amount, and because Canadian mortgages compound semi annually rather than monthly, an American amortization calculator will not reproduce your Canadian lender's numbers.
Run your specific numbers with a lender before assuming a rate move changes what you can afford by some rule of thumb. Get your hand-reviewed valuation from Joel Dyck.