I'd split them up and replant in the ground - the only reason people think they prefer their roots constricted is because the first discovery of this plant was in a place where the roots were crammed under a rocky ledge, just by chance. They flower better in open ground in full sun, in my experience.

That's good news because I just realised I haven't got any spare pots!! Just posted pictures of new cold frame which I trust will come in handy if the weather predictions are anything to go by!

Have split it into three clumps and planted at random in the garden. We will have to wait and see!!!

Sunny, well drained spots I hope...

Sunny yes, well drained hope so as my soil is ok, not too clumpy... Should have put some grit at the bottom of planting hole... Oh well, I was in such a rush to get them dug up, and replanted I didn't think, fingers crossed!

Oh, they'll be fine, a bit of grit won't make much difference, I wouldn't worry about it...