I don't think you should dig them up.

I'm in zone 7 & my cannas stay in the ground year round here.

Debbie is right- your canna are fine. If they don't have great foliage in the winter for you, feel free to cut them all the way to the ground. You shouldn't have any problem transplanting anytime of year as well, although now would be a good time if knew you wanted them in another place.

Lucky you! From what I understand, the only thing you have to worry about is their taking over your yard :) I can imagine, they spread enough here in zone 6, they should really go wild there.

I'm a Florida 9 and I don't dig them. They might get some leaf kill if we get a heavy frost. That's about it. Just remember to keep deviding them when they get too close together.
Sky~~