Water damage is tricky. It can manifest a symptom in many ways, but mask the root of the problem. Typically, water will not damage just a peripheral component (such as the LCD). Rather, the logic board will be damaged, and this damage will manifest through component failure.
My guess is that the snow damaged the logic board, and the non-functioning LCD was a warning sign that the logic board is dying. Regardless of how careful you were (and I definitely believe you were careful!), I think the logic board just finally gave up the ghost.
Those are my thoughts, for whatever it's worth. Sorry!