Last year I learned a lesson on how hard the frozen ground can be. I broke some MSR Groundhog Stakes trying to pound them into the frozen ground. This year I've done the simple thing and used some plastic shopping bags filled with snow and then covered with more snow. Works very well. You can also use dirt to fill the bags. As you know, those plastic bags weigh next to nothing. The handles held up well in the wind last night. Didn't stretch at all - tough plastic.
Just be sure to take them home or to the trash can when your done playing in the snow. I'll be keeping a half dozen grocery bags in my pack for winter camping. They'll also work in sandy areas.