Contrary to the stereotype, I've found they deal with cold far worse than they do heat. They'll push themselves to get out in the sun so they can pretend to be healthy or getting exercise. But they can't psych themselves into balance. Ice on the ground or snowbanks that require muscle enough to jump onto but weight low enough not to sink can't be faked. In my experience at least, they all but disappear in areas that aren't plowed throughly once the snow starts to fall.