Not quite true Ian, the Sky satellite will be in a geostationary orbit (which means that its orbiting at the same speed as the earth so its relative position to the ground never changes) otherwise your dish would need to track it as it moved across the sky. The Sky one will somewhere well to the south of the uk which is why all the dishes point that way. The further north you go the lower the angle will be as well and eventually the horizon will get in the way.
Maybe sky have some sort of roaming agreement so you can get their signal of other peoples satellite?
This link
http://www.wotsat.com/footprints.html shows you which ones cover which area and tells you where they are in the sky.