Dicksonia Antarctica

Hi.
I have a dicksonia antarctica tree fern. I've owned it over twenty years, its about two metres tall. It has always been spectacular, huge fronds, 12 or 13 every year.
I used a hosepipe to water at the top. Gave it some miracle grow liquid feed every spring. Insulated with fleece in winter. It was, very happy indeed for two decades. A few years ago, the beast from the East got it. i insulated too late. It has struggled in the years since, small and late fronds.
This year, no new growth at all. Its not rotted, or mushy, but bone dry and no fronds.
Do I give up, or is there a way to revive?
Ive considered cutting off the top, maybe thats dead, but alive further down the trunk?
Or maybe its completely dead?

 

Thanks for the info. I was feeling very guilty, that id maybe killed a hundred year old fern. Good to know i may not be entirely to blame. I was counting on grafting a new fern on top, but it seems that may not be viable.