I did more research and found that dry area can kill them. I think, my basement is dry even though it's cold. I also found out that smaller rhizomes easily dries out quickly. However, my other small rhizomes are fine.

Should I transfer them to a plastic bag with holes with a little bit moisted peat moss?

Also, I remember there was a suggestion to me that dirt shouldn't be removed very well. I left some. Looks like that could be the culprit. :(

I'll try moving them to a different storage, trash bag with moisted peat moss.

My other rhizomes without the dirt are doing fine.

I have been growing Canna's successfully for 10 years. I store them in the basement every year. I dig them out usually in early November from the ground. You have stored them correctly. They do dry out they go dormant and are resting all the roots die from the canna and become brittle like tiny stems. That's what they do. Come March you should begin to see them start to grow.

I think you are okay. One way to find out bring one upstairs put in water in a dish or bowl near a window and see if it starts to grow.

That's a cool test! How deep should be the water? How many days to wait?

Thanks!