For now I would simply take off the affected leaves, leaving the stump. Uually if they are going to kick back in they will put up a new 'trunk' but it is just possible that it may put out new leaves on the existing growth, which means it won't take so long to recover. If it puts up a complete new growth from the root you can cut it right back then.

You will be lucky it it survives,i'm afraid. Cordalines have really been found out this last winter that they are not completely hardy ,as have a lot of other plants.

Having now done a 'stock-take' on my even more tender plants, Wyeboy, I am not so sure. My Gunnera manicata is showing shoots, which is amazing, both my Cannas (Zantadeschia) are showing through and my smallest tree fern (1 foot trunk), which I thought would be a total write-off may just (JUST) be putting out a couple of new fronds. I never give up on damaged plants without trying. Often I win. See my photos for the poorly Cycad.