Get your good mate to order sky on his address (you could also do it online), have the system shipped and installed at his place. Once everything is working for him, unplug the system and bring it to swiss and start using it.
We have recently moved to Grindelwald, and bought our Sky box with us. This worked because we have kept our property in the Uk, and had Sky installed (with dish) before we left. We simply unplugged the box, retained the viewing card, brought it all to Switzerland and got a local TV installer to fix it all up when we arrived. The key is the UK address - and dont forget Sky have issued a new viewing card.
That's the point - the subscription is based on a UK address where there is no other subscription and, providing you don't to anything to bring the move to their attention, you should be alright.