There's no need to move house to view other ITV regions. Although the additional ITV regions cannot be accessed directly from the digibox EPG, they can be viewed using the Other Channels menu option (press Services 6 on the remote control).
Before they can be seen, you need to use the Add Channels menu (Services,System Setup, Add Channels) to add them.
Full details of the other ITV settings can be found at http://www.lyngsat.com/astra2d.html.
Currently, for ITV Westcountry, the settings are
Frequency : 10832
Polarity : Horizontal
Symbol Rate : 22000
FEC : 5/6
For Meridian :
Frequency : 10891
Polarity : Horizontal
Symbol Rate : 22000
FEC : 5/6
For interest, the reason that some channels give better reception than others at a given location is because there are a number of different transponders on the 5 "Sky" satellites that have different signal strengths and intended reception areas/footprints.
One of the reasons that the unencrypted BBC and ITV channels are specifically on the Astra 2D satellite is because its footprint is tightly focused on the UK. This can cause some problem when trying to view in Spain but hopefully adding Westcountry or Meridian to your Other Channels may help.
Another option may be a larger dish but it's easier and cheaper to try adding the other channels first. Hope it does the trick...
Homer, December 2007