Thank goodness it doesn't snow much on the Great Plains.
Bison evolved to deal with such conditions, specifically a large square head to plow under snow to search for food. But the major strategy they used to survive winter was to migrate south as winter arrived, and then move north as grasses began to sprout in the spring. It should also be noted, that although winter on the Great Plains can be bitterly cold, it really doesn’t snow much - drifts may be deep, but that’s about it. About 60 miles from where I sit on the other hand, it really snows - Mt Baker has had 6 and half feet this week alone. It averages about 55 feet a year, and a few years back they ended up with 95 feet of snowfall. It that case, it doesn’t matter how long your legs are...
So why didn’t rhinos evolve to deal with it? That big horn would be as good of or a better plow than a bison’s head. Bison did not migrate south in any particular pattern. The Canadian Woods Buffalo lives around the Arctic Circle. The Mountain Buffalo lived in the high country of the Rocky Mountains.
Thank goodness it doesn't snow much on the Great Plains.