Paul, That is a shame. Great Expectations are not that easy to grow. Both of mine died. Yours are awesome.
Might I suggest before the digging starts to tape the stems with masking or painters tape. (Easier with 2 people) Gather the stems with both hands and gently pull together. Wrap the tape up near the leaves a couple times around the whole circumference of the stems. This saves from breaking and makes easier to see where to dig and easier to handle.
Most important it protects the capillary action of water in the stems to the leaves. Leave the tape in place for a couple weeks after replanted. Remove tape gently.
DH and I have moved humongous Sum&Substance, Krossa Regals, and Elegans very successfully.
Good luck
