hey, how bout a sock under a winter tarp? that would solve snow blowing in from underneath. then all you gotta worry about is the integrity of your pull tabs. a good large tarp should have heavy duty pull tabs for exactly this reason, there could be strong winds in any season really, but the consequenses of pull tab failure are just more severe in winter conditions obviously. setting up a tarp in cold heavy wind is still a problem, but setting up a 4 season tent in similar conditions isn't exactly easy either, as if you are truly in severe windy freezing conditions you probably want to guy out the tent with several lines as well. something like the fig 9 mini's might be worth using in conditions like these even if you don't otherwise, just to get the job done and get out of the elements quicker and require less dexterity as well, something you might not have for long if you have to take your gloves off to tie a knot in 1.75mm line.
those structural geodesic domes did look pretty cool, could you set them up on uneven ground though?