Food Protocol

When I’m creating my food protocol 24 hours in advance, what should I do if I know I have an event coming up the next day (like a banquet, dinner at my parent’s house, a party) when I don’t know exactly what will be served. Is it ok to tell myself or write down that I’m going to follow the guidelines of my general protocol (no flour or sugar, and protein, fat, veggies)? And then I only eat foods that are a part of my general protocol? These types of situations don’t happen extremely often for me, but probably once every couple of weeks or so.