Ted of Hollyhill Dahlias - doesn't wait for frost to dig. He is digging this weekend. Of course he grows a couple 1,000, and digging/dividing is a week long job at least.
Its kind of tempting to go ahead and deal with it while it is still in the 60's during the day, but I am just not willing/able to sacrifice all of the blooms. The long term weather here doesn't show any signs of frost for the next 2 weeks. Except for some broken laterals the plants are still looking good.