Hi Richard,
I'm not sure where abouts exactly in the north you're looking at, but I love the lake district. The C & CC site at Keswick is ideal, as it is situated on the shores of Derwent Water, and a 5 to 10 minute walk into Keswick, where there's plenty to do. Lots of nice walks in the area too.
Only down side is that it is a very popular site, but there might be something with it not being school hols yet.
A couple of other nice ones i've been to in the lakes are Troutbeck Head CC, (9 miles from Keswick) and Windermere C & CC (4-5 miles from Windermere). Nice walks from the site, but you'll need the car more than the Keswick site.
Good luck finding somewhere!
Lara.