New York, NY
Communal sukkot this year are by sign up only, and we’re likely booked for a late lunch. If shul ends around 10:30, and I want to eat something, and can’t do it in a sukkah, what’s the best procedure re: eating and kiddush?
Eat a kezayit of mezonot and no more. Which isn’t חייב בישיבת סוכה.
Alternatively, rely on Rav Moshe (Iggrot Moshe YD 2:163 and OC 4:63) that you don’t need מזונות to eat at kiddush. Just if you don’t have it you need to make kiddush again next time you eat.