I don't think you can count on a reliable signal with a Sky mini-dish that far into France if you want BBC and ITV. Maybe they have a 60cm Zone 2 Sky dish? It looks the same, but it's a bit bigger. A zone 2 dish should work all the way to the south of France.
Really you need a 65cm dish to be certain of coverage in the South of France. I tried my 54cm dish and it struggled....But a 65cm I borrowed was fine.
It took me a while to figure this out, but I found that you can get other channels on the smaller dishes, but not the mainstream BBC, ITV etc. which are beamed from the Astra 2D satellite. See http://www.lyngsat.com/28east.html for the channels and which Astra 2 satellite they are beamed from. If you click on the "beam" link to the right of each set of channels it shows you a coverage map (which is a bit conservative at the fringes and dificult to understand for some beams).
So in Northern Spain with a mini-dish you could get some Sky channels, but not BBC or ITV.