It's a tough one and the main reason I hate potty training in the winter!! In the summer, it's easy, I just change them outside but in the winter it's a little too chilly for that. I don't like to keep a child in a poopy diaper for too long so if it was a warmer day, I'd probably just change them in the shed or garage. However, we are only outside for 25-45 minutes in the winter and I don't think that's too long of a time to wait until we back inside.