I have an awd Sienna. Live on top of a mile long dirt road/hill. Never been stuck. It goes everywhere all the time. Put winters on it, but no other mods.

In one of the articles about this, they said they've worked with the 'smaller' GPS data providers, and have tried/are working with GMaps and Apple Maps, but those two are very slow when it's a 'rare event' like this.

Same on the Stowe side - they'd have to turn into one of the mountain parking lots or do a 19 point turn in the long trail parking lot if there weren't many cars in it.