Bump this up.
I would be interested in an answer too.

 

Does anyone know the answer to this question?
If not I'll call my local garden center.

 

One of the reasons people aren't answering is that without knowledge of local conditions, it's difficult to make even a guess.

I live in Tennessee and I would hesitate to move them now. Heat and dry stress the plants, so you have to see not just what the weather is today, but what it will be in the next several weeks as the plants reestablish themselves. I know people who say they can be moved in June, but I think that must be in cooler regions. As a rule, I would hesitate to move them later than April. Any planned transplanting I do in the fall.

If you simply needed to change locations, I would say dig up dirt and all and move the largest clump you can manage with as little disturbance for the plants as possible. It sounds as if you need to get rid of the grass, though, so a mass move might not be what you want.

Bottom line, chances are good at least some of them will die. All of them may die. Since you aren't getting much from them now, would losing them be a major matter? On the other hand, is it necessary to move them now? You could mark them now with sticks and dig them later. That would be my recommended course.