Dahlia tubers question

OZZ

Hello! New to growing dahlias. I dug up my dahlias to store for the winter but not sure how to divide them. Read that tuber growing out of tuber is not going to produce any flowers,  but I have one tuber that mostly one at the top and lots at the bottom,  do I just chop those off? Or do they help the plant grow next year? 

Hostafan1

I wouldn't divide one at that size. Let it bulk up more next year then you can divide it the following spring