In reply to bilbo 1: Although not in Keswick or Ambleside the best campsites in the Lakes for me are :
1> Langdale National Trust
Not too expensive, good toilets and showers, drying room and you dont have to pay for parking if your heading out in the valley. Not too far from Ambleside.
2> Seathwaite
Cheap if very basic but with a nice cafe next to the field. Not far from Keswick.
3> Langstrath
£3.50 per person per night, toilets but no showers but when I have camped here in winter no-one has bothered coming to collect my money so occasionally free. And not too far from Keswick. Has that real 'in the middle of nowhere' feel about the place if their aint many people there.
Most campsites in the Lakes seem to be so expensive and I personally refuse to pay £10 or more to pitch my tent for the night (Baa Humbug).
Enjoy your Christmas camping!