I love hydrangeas, and with your weather, (I mean rain, not cold with which I haven't had any experience and thank heavens for that!), you should be thrilled with them. I love the one with some florets in the middle. I have bought so many of them and they are tough (ah hem, I haven't killed them yet!) and the cuttings are easy to take. Definitely an asset. Fatsia I am not so keen. I would go for a variegated evergreen with flowers and berries .. You could also think of astibes (£1 a plant in poundshop - What's not to love? Eh?) How about camellias? I love Williamsii Debbie ( as recommended by Jim in The Beechgrove Garden).
Carol Klein introduced me to
Ribes laurifolium in the 2nd episode in GW and they were flowering like mad in winter. Also Daphne odora aureomarginata (Hehe! I bought this last September) and it has lovely variegated leaves. I myself love viburnum plicatum mariesii. Just bought one for £8! GREAT EXPECTATIONS! 
