Golf variant

I have a Golf variant with a 1.9 turbodiesel, since November 2008. So far there has been one problem: in a snowfall I was plowing through snowdrifts, the next day the car started without issues, but the climate control didn't work. After half an hour of driving, wiping the windshield with my palm to see at least something, it started buzzing and warm air came out. In the morning, the same story, and it continued until I went to a car wash and defrosted the car for an hour. Apparently, snow got into the filter, and there a plug formed due to frost. Has anyone had such a surprise? How can I fix it faster if the car is parked outside?