Arlene, we are just about the same zone. Maybe I'm a tad warmer. I already planted about 25 tubers. Some already sprouted out of the ground. I'm waiting for 12 more from Swan Island. Just got an email they just shipped them - so might be arriving in a couple days.
Awaiting also for 6 tubers from River's. I have no idea when they're going to shipped them. I just ordered from them last week just barely made it in time. Paid through pay pal and got my invoice and receipt. Literally just an hour later went back to their site to 'browse' for more when I noticed everything was "Sold Out", when just hours before - so many were available.
Same thing happened with Vicky's Dahlias. A vendor I just discovered this year since Swan is sold-out of the varieties I needed and I was too late for Corralitos Garden. Found some in Vicky's Dahlias and then some. Ordered last week too - some hard to find varieties. Moments after I placed my order, they closed their site for the season. Phew! Lucky I was! Got my dahlias in 4 days time with a freebie and some of the healthiest tubers I've seen. So impressed with this vendor.
Well at least I got the varieties that I really wanted except for one which I'm really, really sad about. Nick Sr. That is my favorite. Couldn't get it anywhere anymore. Bummer! Maybe next season then.