It just depends on the size of the dog and how long you want to stay outside. A dog will let you know when he is uncomfortable from the snow by lifting up his feet, but by then you pretty much need to take him in right away. Small dogs might start lifting their feet right away, while larger dogs might romp around in the snow for 20 minutes. For potty breaks and short walks, you don’t need booties, but they can be helpful to prevent salt getting in between paws.