I think your best bet outdoorgirl would be to dig it up and pot it up. Keep it in a sheltered spot until Spring. When it starts to show shoots, plant it out (after frosts have gone away).
With the wonderful benefit of hindsight, if you needed to do this in future, take cuttings. You will therefore have young plants, and if the old plant doesn't survive, at least you have something to replace it with. ;D
valmarg