So the Islay Ferry actually goes out of Kennacraig - on the Mull of Kintyre (https://youtu.be/AcZVRiB9AQk) It is a trek to get from Glasgow to the Ferry - 2.5 hours. The Early ferry run would be a stretch. (oh and you can fly) Campbeltown (Springer and the other springer family beverages) is about an hour down the road from the ferry dock. So it maybe possible to head from Glasgow - play around - end up in Campbeltown for fun. Either stay down there - or catch the late ferry over to Islay. Note - if Islay is on the table book accommodations early, it is a small and popular isle, If the group is big enough I would say a house or cabin. Otherwise there are accommodations in Bowmore and Port Ellen that can work, (Lochside Hotel has a nice whisky bar) I love the highland area as well around Aberlour and Rothes (but that is another story all together)