I'm driving into town to get a support pole this morning. But I'm still wondering. I need that blind for gun season here in two weeks. I am leaving today so going out there and brushing off the blind isn't an option. Taking it down is s terrible option too. It's on an elevated platform all screwed down and is already stocked with the gun hunting stuff (chair heater etc). This is a barronette bell bottom blind.
Snow can also vary in weight whether it's wet or dry snow. I'd say more than a few inches and you're going to have problems. Maybe get out there before the snow flies and build some wigwam supports over the top of the ground blind for support. NativeTech: Wigwams - Basic Wigwam Construction Once you've got the skeleton built, start from the bottom and start placing branches, leaves, etc. over the top. It'll give you support for the snow, and some more insulation for the Winter.
If there is an eyelet on the top peak of the blind, I'd maybe try and have that tied to something above the blind. This might do a better job of keeping the slope of the blind up and snow sliding off. If you are really concerned, you could always spray some PAM on top of the blind to help the snow slide off.