I tend to think that time (for the snow to evaporate or re-freeze) and recharging the battery had the most effect. I don't understand why mechanics suspected the PNP switch when the starter was operating, but have to admit there is absolutely no substitute for experience. They must have seen this cause-and-effect relationship before, and there probably is a good explanation.

I am really glad to hear you didn't jump a cog on your timing belt; that would heve ruined your week for sure.

A lesson: I've lived in the Northeast USA all my life; as kids we were taught never to park outside facing the North or East if a snowstorm were forecast. Wind-driven snow virtually never came from the South or West.