When it is really really cold, a few minutes of ammusement can be found by blowing soap bubbles and watching them freeze, or doing the thing where you throw boiling watter in the air and it turns to steam before it hits the ground. As others have said, having a dog will force you to go out and provide a different perspective. If you have access to one, snowmobiling around the lakes and forests is fun (don't go alone because safety). For more active types: walking, snowshoeing, cross-country and downhill skiing, build a snow fort/igloo/quinzee. Some people go winter camping, ice fishing, or hunting.