He also said that structures are built to withstand significant snow loads--to local code (our blizzard was, hopefully, the last one that size we'll ever see!) In our area (probably yours as well), the snow load (pounds/sq ft, I believe) can be easily found through the county; even on their web page.
During/after the blizzard, I did try and remove some of the weight from the roof. But I couldn't reach all that much of it, and I certainly didn't want any/all of it to come down on me! And I wouldn't want to fall off the roof, either.
Anyway it did sound like stress cracks (like in corners) weren't all that uncommon after the blizzard. There were some building collapses, but not many, thank goodness.
Anyway, this is not a direct answer to your question, of course. But in my personal experience, my mind was set more at ease about having a fair bit of snow stay up there.
So, all that said, how much snow are we talking about?