I suspect you will have to fleece it.

I think it depends where you live, and what position you place it in - we have one in the flats where I live in west london, out at the front, which is southfacing, but pretty exposed, although the tarmac of the parking area 2 feet in front of it helps to raise the temperature around it. It grows against the sitting room wall of the ground floor flat, has been there over ten years, has come through this winter, although all the topgrowth was dead and had to be cut back. And in case you think the temperatures are much higher herecos it's London, they're not - I live opposite fields, and we get an awful lot of frost here.

thanks for your answers, I feel more hopeful now!