score:2
While the VSRP hydrofoils stop running as soon as the tourist season is over in late August, per WayToRussia the bus+local ferry combo keeps operating until Lake Baikal freezes over completely in December.
https://waytorussia.net/Baikal/Destinations/Olkhon.html
I found the avtovokzal bus schedules to be 100% accurate last month (not really surprising, since you can also buy tickets online), so I'd suggest keeping an eye out -- they'll publish the new schedule sooner or later.