Party RSVP and food?

[2anddone]

Hi my dd is having a party the first weekend back at school so I sent out the invites the last week of term. I have heard back from almost everyone apart from 5 families. I am doing 'reminders' for the first day back at school along the lines of ' hope you hAd a lovely summer holiday, we look forward to seeing you at party on Sunday' do you think for the 5 that have not replied I could put 'hope you had a lovely summer holiday, if you are able to attend party on Sunday please let me know by Friday so I know for catering'
It Is a disco party but I am doing BBQ food so need to know whether they want hot dog or burger. If they don't reply do I just buy 5 extra sausages and 5 extra burgers on the off chance they turn up? Or do I let them have the carrot, cucumber, tomatoes, crisps etc that will be available --tempted to not give them a party bag
either as think it's bloody rude not to reply-- would love to hear opinions thanks

[Hoolit]

Its infuriating, I know. My dd had a party in hols and five did not reply and did not turn up, 1 said was coming and did not arrive and I had to pay for 10 regardless that only 6 came!
I think a reminder might be a good thing, I certainly would not take offence whether I had replied or not but if you decide not to get in extra food as it can always be frozen and they get whats left and used as a tea at some point.
Party bags is difficult as kids love them, mine where supplied but I had bought loom bands and bubbles as extras but they were cheap ie 2 loom bands a £1 and bubbles 1p for 6 so just shared the excess with kids that arrived.

[Hoolit]

*not not iykwim!!!