Joyce,
I use Sky+ in my van and it would appear you are making the right preparations for you to be able to do so. However, are you sure Sky have said you can use your card anywhere. Remember your card is dedicated and configured to your Digi box and will not work in any other box, According to their conteact you normally have to leave your box connected to your phone for 12 months or if you have yours under a special offer, for longer. also the contract will also say the card is for use within the address it was issued to. How you play it is up to you - join the rest of us and take your card and box with you.
Good luck JTS.