We've never done the bootie thing. The only reason I'd do that, though is not so much from the cold as the salt. That can do some serious damage to paw pads, not to mention that they will lick their paws and get sick. Luckily our township has determined that salt in the residential neighborhoods just cot's too much so they dump cinders when it snows ... and our neighbors are much to anal about the condition of their sidewalks to ever put any of the aggressive melters out there.