the cordaline i would weight till spring and cut the damaged leaves of.to stop this hapaning in the future i would and do pull all the leaves up over the growing tip and tie or use electricians tape of a bright colour so you can find it them up above it.this will stop the frost getting in and stop the snow having anywear to lay which i believe has bean the mane problem as apposed to the cold.

If the leaves pull off easily, then remove them now - otherwise wait till late spring and cut or pull them off then. The weather should be slowly improving in terms of temperature now, so we should be through the worst - but Nosey is right in tying them up by pulling the foliage up vertically, and then tying string round at intervals to keep them up in the air to protect the growing tip, wrapping in fleece - this is for late next autumn, though, don't bother now, it's too late for that this year.
Photinias are often used for hedging, and respond well to pruning - but (unless you're desperate) I'd suggest waiting till the weather warms up before pruning - late April/May.

Thanks for the quick replies, I will wait until spring to carry out the work.

Thanks for your help.

your more than welcome denno.