Hardiness of yacon for overwintering

So I started growing yacon last year and dug up the crowns to overwinter them since we have cold winters (USDA 5a). They're in pots with soil right now, somewhat moist, but not that moist (haven't watered since late October). Currently they're in the garage which has been around 3-4C thanks to the mild winter weather but over the next week it will get quite a bit colder in the Great Lakes so the temperatures in the garage might drop a bit below freezing.

My basement cellar is a bit less cold - currently 6C, but I wouldn't completely rule out the possibility that it goes below freezing too since it's not that well insulated. Hopefully not, but I just moved here so it's my first winter and I don't know how cold the cellar will get. It was about 15C during early fall but has been getting steadily colder.

I've heard the crowns can withstand light freezes when dormant? But I haven't tested that myself... should I keep them out of freezing temperatures to be safe?

I've had Yacon overwinter in pots outside here, where we get light frosts (not less than -5 Celsius), although I didn't mean to leave them out! I would move them to the cellar to be on the safer side. If you have several, you could move one to the house, somewhere cool just in case, but I suspect they will be fine.
As long as one plant is safe, you can divide it into chunks with growing tips in the spring, like dealers do. Although the plants will not be as big, they will soon grow away with a bit of good compost and catch up with larger crowns.

i suspect the idea of yacon surviving light freezes while dormant is about when they are still in the ground, with all the thermal protection that affords - as in the yacon itself doesn’t really freeze much itself, even if it’s freezing above-ground. my experience is that freezing is almost always hugely damaging to yacon. report back if you find out otherwise!