Ten to fourteen days seems to be the suggested time which allow eyes to form for easier dividing. Steve S.

Um, 10-14 days from what? BTW, I divide in the spring, which is much easier.

My question pertained to how long can they stay in the ground under the current temperatures (if they remain stable as described)?

My guess is that you could dig them any time before the ground freezes. Don't we just dig in our zones b/c the ground freezes?

Steve S. 's answer was right on. Swan Island says to leave them for another two weeks after the killing frost. I finally dug mine up yesterday, it had only been about 8 days since the killer frost turned them form gorgeous to frighting, but I had the time and it was up in the 50's here yesterday.

I was feeling depressed that growing season is over, but looking at the size of all of my tuber clumps makes me start dreaming about how many more I will have next year.

Anna: I've never been successful in overwintering, but I'm trying again this year. I think I always dug them too early. I contacted Swan Island Dahlias and they said to wait two weeks until after the leaves turned black. In instances where there is no killing frost, then they are safe to dig around mid-November.

Thanks everyone!
Bad news: I never did get around to digging out the dahlias - too cold and even snow, and I was at work.

Good news: DH (amazingly) offered to do the deed. I would normally never expect him to do this, but he saw how sad I was to lose all my plants - so he did it!

Good husband, Anna! He's a keeper himself!