I did a cruise before Christmas and just kept to low carb (including fantastic bacon & eggs breakfast etc) and I stuck to drinking water. I thoroughly enjoyed it, enjoying delicious meat and fish (I guess effectively going Atkins for the 2 weeks), and I continued to lose weight, and probably stayed in ketosis I guess. I really would avoid the free bar, enjoy the food sensibly, and then you will be able to stay on track. Although I guess you're very close to target, and may even have reached it by then. It's up to you how sensible you want to be, but if you want to add alcohol in, then please be sensible and add some food in too, so that you don't get ill!