Welcome to the forum. It would depend on which package you have, eg. the Combo or the straight broadband, and whether there is a combo discount on your account - if there is then cancelling the pass would increase the cost of your package, which might mean it's not worth doing.
Best thing to do is give the Broadband Team a call and ask them what price your package would be if you cancel the pass, you can then decide for yourself if it's worth doing or not (you might also want to see what the affect would be of changing to a different pass, if any of the passes are more interest to you).
You can find the telephone number for the Combo Team by going to your My Account > My Package page (look in the moving house section)