When my heuchera are a reasonable size or too big for their pots I just split them so that each piece has plenty of root. I have some in pots and some in the garden and find them very tolerant of being moved and very easy to grow and split.

I have taken cuttings now and in the spring. kept frost free in a cold frame or unheated greenhouse.
I usually check ones in pots for vine weevil grubs about now, at the end of summer so they don't get eaten over the winter.

Thank you both for that I will try it tomorrow and in the spring.