The groundhog has won. Not even Plantskydd has won. I read about one woman who has bought a wire garbage can and placed it over her milkweed plants, anchoring it to the ground so it can't be knocked over - now that's a direction to which I will not go!
The one consolation I've heard is that milkweed is highly invasive, and I could see that with where the one plant from last year spread, and a messy stand of them would probably make my landscaping look very sloppy.