There was not a single question mark in your post, which makes it unclear of what you are looking for.
Carbon fiber will only deteriorate if you smash it with a hammer or something; but that's under perfect conditions. If well taken care of, a CF bike will last longer than you will. I would be more worried about the components on the bike than the frame itself if I were to ride it in the snow.
Since I wanted straight answers and not just opinions - I asked the corporate reps and engineering staff at the technical seminars. The post here was just to pass on that info.
Your opinion of CF bicycles is very different from the opinion of the people designing and marketing them.