I just did the Coq, there was no snow on it either direction (Rogers' Pass was a different story!)
AP did great on the Coq, but for 2 issues, 1) the range estimates are out to lunch, most likely because of 2) BC has upped it's speed limits, Tesla's nav doesn't know this, and therefore it keeps popping up speed limit signs on the dash that are wrong, even when it hasn't passed one in a while, they all show about 10kph too low. Additionally, the camera didn't correctly read a single one of the many 120kph signs on the Coq, I suspect it's because the car thinks speed limits don't go that high. it got quite annoying actually.
As for the snow in Rogers pass, no idea how the autopilot would do, because I wasn't stupid enough to use it. You'd have to be remarkably dumb to do something like that. Every cruise control system out there always warns you not to use it on snow or ice, or even in heavy rain, Tesla's system is no different, it should never be used in those conditions under any circumstance.
That said, I can guess how it would do, it would be smarter than the idiot who wanted to use it and simply refuse. I know this because it couldn't see the lane markings, which disabled the steering wheel icon on the dash, and snow packed in to the front radar which disabled the cruise icon on the dash. Both would have been unavailable had I been dumb enough to try them. I did however find that the car performed beautifully, despite being a high performance rear wheel drive car, and despite the many vehicles in the ditch (I counted 2 mini-vans, 3 SUVs, and 8 tractor trailers) I never once felt any slipping, sliding, or loss of traction, the car handled perfectly. of course I also have winter tires (not all seasons) because going through the mountains any other way is asking to be one of those vehicles upside down in the ditch.
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Highly doubt it. But I bet they left room for one in the design of the store. I just don't think they've built enough of them yet to get them in to the malls.