OK I don't have a chart to hand, but looking at various other resources there doesn't seem to be any airspace close to hand at Bowland Forrest - the base above is above common UK thermal levels, and the stub of the MATZ is plenty far enough away.
You might also fancy investigating Eden Soaring. It's winch only, they had a professional instructor last summer, and it has ready access to probably the best ridge in the UK. It's near Penrith and apparently starting again on 1st May. Challenging I believe but will be fantastic and mind-blowing in the right conditions.