Where in Uk are you ? Welcome to Goy.

I am in Scotland and have many fuchsias but mine do need protected in 2012 I lost all mine in an unseated greenhouse to the long cold winter.

Many yrs ago when I had a trench in my greenhouse I used to bury all my fuchsias and never lost any.

But for this winter I have taken all my fuchsias into my conservatory for the winter ,a month ago I pruned them back and now they are growing new shoots again as it's so mild

You need to protect the pots from freezing, because that's what will kill them.
If it's an unheated greenhouse this might be difficult, depending on where you live, and where the greenhouse it situated.

I would suggest you cover them with bubble wrap. Layers of newspaper will also act as insulation.
Keep them on the dry side, and I would also ventilate them on dry days to prevent mould.

I think a shed would be a better place to keep them ... or a garage. I keep mine in the old outside loo.
Also burying them in a trench as Scotkat did is a good idea.

I live in Scotland too and a cold greenhouse is too cold for Fuchsias.

Here in the midlands it depends very much on the winter, last year fuschia, pelargonium and osteospermum flowered on and off throughout in a double glazed cold greenhouse. In the winter of 2010 I lost the lot.
I tuck them all together for warmth and if bitter weather forecast insulate as Hywel says......

I keep mine in the garage,wrapped in newspaper/bubble wrap and I make sure they don`t dry out.I do loose the odd one but,generally, most survive.Good luck.

That's interesting Huffmaling. I overwinter mine in the conservatory now, keeping a few leaves going, but when I had only a cold bedroom I used to let them dry out completely and they did start to grow again when watered in spring. Has anyone else tried this?

I usually manage to overwinter fuchsias in an unheated greenhouse, but I am right on the coast in the North-West of England and it's generally very mild here. I hardly water them at all, and cut them back in spring when they start to show tiny green buds.