Kaffir lilies killed off by snow??

[Smithagain]

I have a beautiful clump of Kaffir Lilies in my garden, given to us by my MIL. They've been in three years and spread out each year with minimal maintenance. I did dig out a clump and divide it last year, which seemed to just make them stronger.

But they got buried under two feet of snow in Feb - which is kind of unheard of in Surrey. And last year's leaves are clearly dying back. I think there might be some new growth underneath, but it's all looking a bit sad.

Any thoughts/advice how to mollycoddle them back into life?