my cordyline has turned brown and appearsto be dead what should i do with it

I lost 7 of mine in the recent winter, I have cut them all down but left the root in the ground, one is growing back from the bottom. It used to be one straight tree, now I have at least 7 new growth all around the bottom of the one tree, see my recent picture, the shoots are grow quite quickly too. I would suggest you cut it down but leave the root in. Good luck! :))