My mom, who could make any plant live and thrive, (or divide and thrive) would use a large pot and put several inches of leaf mold in the bottom. Dig up the plant and place it in the pot and cover the roots with more leaf mold. Then water well. Get it to the new location and get it back into the ground as soon as possible. Then water daily for a couple of weeks. Don't overwater, you don't want to drown it, but making sure it has good drainage in the new location, water to keep the roots moist all the time. And plant it with plenty of that good old leaf mold around the roots, to keep them cool, moist and properly nourished. Mom never used chemical fertilizers or root stimulators, just whatever she had on hand, usually just leaf mold.
Cheryl

Yes, I've moved them when fully leafed out and they never missed a step. Water well before moving, keep the root ball intact and don't plant too deep - roots just below the surface of the ground.