Fewer new listings in the fall does not mean fewer good houses. Owners who list outside the spring rush are often motivated by a real deadline like a job move or downsizing already in progress, which can make them more open to negotiating on price or possession date.
The market's overall pace, 1.63 months of supply as reported by the Saskatchewan REALTORS Association, still applies whichever season you search in. What changes seasonally is how many other buyers you are up against for the homes that do come up, not how tight supply is underneath that.
A fall search can actually work in a patient buyer's favour if financing and conditions are already sorted out before the right house appears. Get your hand-reviewed valuation from Joel Dyck.