I bought a few special daylilies very late for my zone last year. I potted them in 3 gallon pots and then planted the pots in the ground where I was going to plant them this year. My plan was to pull the pot and bring it inside in case of a really bad cold snap. We didn't have one so after six weeks I just left them in the ground in the pots.
This spring I pulled the pots and then pulled the plant which kept the shape of the pot and fit the hole in the ground. It worked pretty well. I did have one root ball break up but that wasn't a problem as I just planted it like a freshly dug Daylily.
Good luck!