Moving it now will not give it a chance to get settled and its roots established before winter comes. What I do with mine when they need to move is to do it in the spring after the ground is thawed enough to dig ( April/May). Mulch it well all around the base of the plant out to the dripline for the winter - 1 foot of mulch is not too little, more will help it if winter is really severe. You can use regular mulch, compost, branches, leaves held down by branches, etc.....as long as it it thick and even all the way out to the drip line of the plant. This will help cover the majority of the rootball. Don't worry about the stalks and stems, they will die off anyway during the winter and will regrow from the rootball next spring. When the big day arrives in the spring to move it, make sure the new hole is big and that a good amount of compost is in the bottom of the new hole, as these plants are heavy feeders. Trim off the stalks on the plant, and dig up the rootball- it will be bigger than what you might expect. Once you have the root out, you might see tiny shoots starting just under the soil level, these are going to be the stalks for this year's flowers. You can then replant the rootball and water and mulch well. If you decide to split the plant, you will need some of the tiny shoots on each section of the root ball in order for it to flower this year. Splitting the root ball works well with a serreated knife ( like a bread knife reserved for the occasion) or with hand pruners. I have used a shovel as a last resort , splitting them straight down, and they have not seemed to suffer for it. I hope this helps.