Hi, Leo. I was planning to overwinter my I. batatas but when it was outside drying, we got a frost and it turned to mush. Thank you for the info: "They can be overwintered completely dry, above freezing, on a shelf or even in the dark of a closet or basement. Succulent vendors tend to carry succulent morning glories. Arid Lands and Out of Africa, both in the USA, often have them. Another place to ask questions about cacti and other succulents is the cacti_etc mailing list, which has something over 2,000 members worldwide when last I heard."