The Isle of Wight isn't a very good island to defend. 1. Its hard to get to 2. It has a population of over 124,500 at any one time and that numbers growing 3.Bad weather. If power cuts out you could freeze.(but then again maybe the zombies could too?)
But on the upside it's well connected with the outside world so knowing when the government tells us its safe to go back shouldn't be a problem.