Personally I would wait until the last moment. That is just me. The way I look at it is as long as the ground doesn't freeze they are better off outside than they are in storage over the winter. I think it best to store them for as short a period of time as possible to maximize survival rate.

I am having the same problem, I want to dig up the canna lilies before the weather is absolutely dreadful (I am in SE WI) but it keeps not getting cold enough. I pulled my gladiolas out too soon so am determined not to do that to the cannas. But for heaven's sake, this global warming is toying with me. You would think that in WI by Nov. 7 we would have had a bad frost, but my raised beds haven't gone under yet. I keep being amazed at morning glories blooming every day, admittedly not at their best but still a few blooms. I picked my last beans on Friday, still picking a few tomatoes and tomatillos.

Marcia

I'm waiting too. We still haven't had that killing frost yet, either. I think Zone six is iffy as to whether they will make it through the winter outside. But, I am new to cannas, so my advice isn't worth much ;-)

I went ahead and dug them up yesterday. It was a really nice day for working in the garden, but it's rainy and chilly out today. I really love this canna (Tropicanna) and didn't want to take a chance on losing it. lol Well, now watch me kill it by not storing them correctly inside!
Thanks for the help everyone!
Cathy