We also had the same problem and have cut it down to about 2foot from the ground. With the mild spring it doesnt look too bad so keeping our fingers crossed. Theres nothing to lose so dont give up on it yet. Good luck.

A number of my clients have these and other Phormiums, and i dont think the prognosis is good, all foliage dead and having inspected deep down into the base have found that they are wet and sodden with signs of rot, all foliage has been taken away and will persivere for a while longer just to see if new swords are sent up, but here in the east mids it was very severe in Dec, julien.