I think it would be a major surprise, but Cav has got street smarts and he has a strong team around him so never write him off. Plus the race is quite sprint heavy.
Would be great for him to pick up a stage, can't assume he will stick around beyond the first week. Last year everyone thought he'd lost his touch, and I remember hoping for a stage win. Look how that turned out.
Surely even a single stage win would be pretty unprecedented after the year he has had?