We kept joking that it was going to happen, but then this morning it did:
The snow actually burst through the glass window and screen into our home. Thankfully it was just the enclosed porch. All other windows seem to be holding sound. For now.
So far this winter, we have had nearly 130 inches of snow, which is the biggest snowfall on New Hampshire record. (The record, inexplicably, only dates back 30-something years, but still.) This house has been withstanding the elements (give or take a few floods and broken window panes) for over 100 years, so while it may have lost this battle, it is winning the war. But maybe we'll steer clear of windows for the time being, just in case.