Real Life Mystery In My Old Hometown Area: Strange Case Of Tanya Shannon

That’s pretty much the default assumption.

Considering the weather, location, and potential time-lapse between wreck and the wreck being found, it’s not entirely clear she’d have survived even if she stayed with the car. Better chance, for sure, but not a certainty. Not a whole lot of good choices, though she took the more risky one. At least she died trying.

Ferret Herder, thanks for the update!
Sad end to an odd story, but as others have mentioned, quite amazing she made it that far, in that weather, dressed as she was.