Getting people to RSVP has been hard work. Still got some outstanding and I've decided I'm not going to ask again. If I don't hear from them by the end of the month, they're not coming.
My next job is to get everyone to let me know their menu choices for a three course meal.
How can I politely say that if we don't hear from you by such and such a date, you will be given x,y,z as a default?