Here's Lycoming's take on it:
http://www.lycoming.textron.com/main...ldWeather.html

I don't see that they warn about destroying the engine.

It is interesting that Lyc only says to expect "minor" wear
abnormalities with improper cold weather starting. That is pretty
watered down compared to some of the gloom and doom stated here and
elsewhere.

Until somebody is prepared to take a shiny new engine, cold start it,
and immediately tear it down for inspection, we may never know.

Good Luck,
Mike