Interestingly polar bears (which evolved from brown bears during the last ice age, have many of the same adaptations for cold. They are very different phentotypically, but are genetically so close to grizzly bears that they can still interbreed. Like the snow leopard, they have smaller ears dense fur undercoats, and fat storage to reduce heat loss. But they also have black skins to maximize solar warming, channeled to the skin by white hairs that serve as light channels.
Warmer climate has reduced pack ice in the Arctic Ocean, so the polar bears are now coming ashore to look for food, sometimes coming into the range of grizzly bears. (or garbage cans by people living in the far northern areas)
And yes, we are starting to see pizzly bears (or grolar bears), the result of interbreeding between grizzly and polar bears. Climate change might cause the extinction of polar bears, not by loss of habitat, but by hybridization with grizzly bears.
The Canadian lynx has a number of cold-weather adaptations found on the snow leopard, which are examples of parallel evolution between closely-related organisms.