Much of the Med should still be pleasant at that time of year, so you should be fine but you might want go a bit more South than your initial thoughts just in case. Malta should be nice and there's loads to do for an ickle place. Take your pick of the greek islands, something for everyone though they're just over the 3 hours threshold. Only guaranteed good weather would be the Canaries but 4 hours. Lots to do activity wise but they tend to be a bit resorty and dull if quaint, historic, walking etc are your bag. How about around Almeria, a nice roman town, cabo de gata has some of the best unspoilt beaches around and it's the sunniest spot in Europe too!