Necessity is the mother of invention.
I'll pass this along in case anyone ever needs to know. In a pinch, a plastic dustpan will substitute for a frost scraper. It cleaned the windshield quite well for me a couple of mornings this week, and it seems unlikely to cause scratches.
The spatula works pretty well too, but I'm afraid I might scratch the glass with it. I mean the pancake-turner spatula, not the rubber-scraper spatula, of course. The rubber scraper doesn't work too well.
I do have a couple of real frost scrapers. I'm just not sure where they are. I think they were removed from the car when we went camping.