Put them in a dry, cool place either in peat moss, sawdust, or potted and let them be. The sprouting will slow and they will be fine come spring. I leave mine in pots all year in the basement (65-67 degrees) and they always sprout a little. Come spring I repot in fresh soil, some time release food and they are great.

Grancru

Hello;
I have overwintered cannas. I divided them into 5 tubers & have put them into two 8" pots, half burying them. They are in a room with 20C temperature but not in the light. Some of them have sprouted green leaves. my question is ,I did not fully bury them. is that a problem? Also they aren't getting a lot of light.I plan to move them out in May. Will they survive inside till then.