My son is having his 5th birthday party this Sunday, his first class party and my first time planning one! Annoyingly quite a few people haven’t RSVP to the invite. I have done exactly the right number of party bags, but worried in case people who haven’t responded turn up. Would you make spares? Can’t afford to do loads more but don’t want to be in a position where I’ve more kids than supplies and can’t exactly single out the ones whose parents didn’t reply. Aware that people who did say they’d come may also drop out on the day. What is a sensible buffer?