I recently bought our many pots of pelargoniums and begonias indoors, where they'll stay overwinter. We did the same last year, though just with pelargoniums and they survived happily, so I'm hoping for similar results this year. I haven't tried this with begonias before and after reading lots about waiting for the foliage to die back and lifting the tubers (an ordeal that sounds, to me, like a lot of hassle) I decided to follow Amy's advice and just keep them in the pots - let's see what happens.