Of course, my friend, you can leave begonias in pots during the winter! All you have to do is find a cozy spot for them where the temperature is between 40 and 50 degrees Fahrenheit. A shed, garage, or basement would work great, and they'll be right at home. You can prune them if you like, but it's really up to you. Just be sure not to overwater, as this can make the soil surface too moist and muddy.