Tuberous begonias store well over winter

Q. I’ve been surprised at how long the tuberous begonias I have in hanging baskets have been in bloom. They are still full of flowers, but there must be some point at which I’ll have to bring them into some sort of shelter for the winter. How and when is this done? I’m presuming that the tubers can be stored and saved for planting in the spring.
A. I’ve noticed over the years that some tuberous begonias are more cold hardy than others, staying in fairly good condition and