What dish for a Sky box

Francis

Hi all

I have managed to aquire a sky+ HD box the exact same as the one we have at home. I would like to take it away in the motorhome so that we have all our sky channels am I right in thinking that I  can do this if I take my sky card from home? Also what size
of sattelite dish do I need will my one from lidl work not sure of the diameter but it isn't too big.

Many Thanks!