Jerusalem artichokes

I'm hoping to grow the fuseau variety of these next year.  If I am going to save some of the tubers for the following year how owuld I do that?  

They will almost certainly re-grow from volunteers

I usually cut them down to a few inches in November when they have pretty much died back.  Then dig up as required over winter (as long as ground diggable).  just been away a week, itching to get to my plot and it's a howling gale and rain.  Potatoes still not all dug.  Sometimes so difficult to scrounge time - the most precious commodity.