My digging and dividing method ( for my most treasured tubers) had been sawing/cutting the tuber clumps into quarters or thirds. One chunk goes right back in spot I dug it from. One chunk in alternative spot outside, like a different raised bed. All others I wash off divide then Saran Wrap up to store in the garage. I’ve had similar success with leaving in ground and Saran Wrap last year.
I’m also gonna try to give away tubers to my friends who grow dahlias nowwww vs later so less stuff for me to store.
I read once that you can in theory plant perennials (rated for your growing zone) any time of year….of course there are times when a plant might have more success or might miss a bloom window. But planting at the “wrong time” isn’t always a death sentence for perennials. I mean if you’re in zone 5 planting dahlias in winter yes it might be a death sentence but what I’m talking about is plants that can survive your zone.
Last year I gave my MIL tubers in the fall probably around November and she planted them right then in November. Of course they didn’t grow since it was cold in Nov and they risked rotting with all the rain in the PNW. In the spring/summer they grew into healthy blooming plants! I also planted a peoney root in June….it grew a couple sets of leaves then nothing. However the next year it grew tons of foliage and had 2 blooms! So planting at the wrong time in Jun was totally fine. If you’re in a mild zone why not try it out with some of your less favorite tubers.