We overwinter our Cannas' and Elephant Ears in wood shavings or perlite. We pull them before a hard frost, rinse all the soil off, let them dry them on newspaper or the like, in the shade. When they're dry, pack them in the wood shavings or perlite. We use old milk crates, lined with a plastic bag. A layer of shavings, and a few roots, another layer of shavings, a few more roots and so on. We usually overwinter in our crawspace. We may use the spring house this winter. 55 degrees in there in the winter. I am far too high strung and always in a hurry, to watch the vids above.
This is what has works for us. We've had the same Cannas' and EE for 20 yrs.!