Good blind idea.
I used snowshoes to get out and across the frozen woods and fields worked much better than post holing although still quite noisy. The snowshoes came in handy to dig the snow and pile it up for a hidey hole and as a "table" to keep the calls at ready. Using your sheet idea- could have stuck the snowshoes on edge and draped it over.
Also put white waterproof first aid tape on my gun to break up its outline.
Given the snow cover winter turkeys proved to be very, very challenging. Not to mention rewarding. You waited for a gobbler WOW. [:-]