Would love advice from those who have successfully overwintered and divided alstromerias.

I have two alstromerias which bloomed all year in pots. We've now had some frost,(Alberta) and it appears the pots are full of roots/tubers.

From a long thread several years ago it appears people have had success in overwintering, but I'm not clear on the method from here.

Some seem to put the entire pots in the basement and then bring them out in February/March...start watering and replant toward spring. Or is it better to divide and repot them now? Do you need a 'cold room' suitable for storage of potatoes, etc.--is the normal finished basement too warm for this?

What should I be doing at this point? Do you dry out the plants? Remove them from the containers...or just tuck the whole thing away until the new year?

Sorry for such specific questions...more experienced growers would no doubt know what do do. The alstros did so well this year I want to maximize my chances for keeping them over! Thanks!