lynne,
You say you have two sky boxes at home. If you are on Sky's multi room deal then you may have to use some caution when taking your box from home with you. Part of the multi room deal is that you must have all your boxes connected to the one nominated phone line at all times. I believe this was to stop next door neighbours getting cheap Sky. They can and do check up on this, we received a polite but pointed warning when,unknown to me my grandsonwho ,stays with me, unplugged his digi-box from the phone. I don't suppose it would matter for a day or two but they do notice and can change your fee tariff if they think you are not complying with their guidelines. As others have recommended try Davis Sullivan's site, satelliteforcaravans, excellent, and David is good at replying to any email queries.
Robert