Hi Chris, check out all of my previous threads as I'm local and have fished right through the winter, on fly only, for the last few seasons, and not just for grayling or pike either!
Last winter I fished the local Leicester brooks about 30 times and only dry netted once. In other years I've fished stillwaters right through catching roach, gudgeon, bream and carp in Jan/Feb. I even broke the ice one day and still had roach and perch.
This thread will give you an idea of what I was up too last winter, if you check out the link on post #7 that will take you to a list of river fly paterns-proven over many years of coarse flyfishing.
Winter Rivers UK Style
Oh yeah and come to out fishing meetings...held on the first Tuesday of each month.
Dee