With a bit of luck they will carry on for a long time yet. The frosts will turn the leaves black probably and that's the time to cut them back .
Some people leave them in the ground and cover them with a good mound of compost to protect them over the winter and some lift them.
If you are going to lift them you need to let each tuber dry out somewhere indoors so the remaining earth can dry off and then be cleaned off as much as possible.
There are different ways of storing them but I wrap each tuber in newspaper and store them in a box in the garage and that seems to work well for me.
Label each one because if you are like me you will forget which is which

About 2 weeks after they have been blackened by the frost you can cut the stems back to about 6", lift them and wash off all the soil, then put them upside down somewhere dry for app 3weeks, there are several methods of storing them, I prefer to put them in dry peat in boxes and keep them frost free.