Nearly Green, we had to move a Peony for sentimental reasons when family member died. Knowing they don't like disturbance I was worried. It was planted in our garden and then 5 yrs later we moved, it lived in a pot for 2 yrs and then finally I braved it, split it into 3. I have 2, in different locations, hoping one place would suit, and a family member has the other. All three have flourished. I did prepared bed / planter beforehand and took as much rootball as possible and did it quickly.
The original one was from my Mum in laws, and it had been transplanted from her Father's. So it must be over 40 yrs old. I hope you're successful.