Inevitably, something will go awry.  Someone will say something you (and they) wish they hadn’t. Schedules will get off track. Something will happen with some food. There’ll be something. Even with the best planning.

There is no such thing as perfection. Not for one day and certainly not over the whole yom tov. Expect that something will happen. You’ll be less frustrated and disappointed when it does.  And if nothing actually happens, then you’ll be pleasantly surprised.