Obviously i don't know where you are, so this may not apply to you, but we have had the mum of a child who's just joined one of my children's classes trying to take over and arrange class Xmas drinks.
We are quite a long way through primary school so we have years of knowing what works/doesn't. She keeps saying that everyone is being boring and antisocial for not agreeing to come, but she hasn't realised or thought about the fact that the majority of the families in the class are either:
Muslim, so won't come to the pub
Jewish, so can't come on a Friday night (when she has organised it)
From other cultures where it's not 'the thing' for women to go to the pub in the evening
Single mums or have very young babies
On top of that, for some reason about half the class have December birthdays, so it's a relentless round of parties etc. anyway as well as work dos, Xmas performances, and so on. Over the years we tend instead to do gatherings in the park at the end of the term, so people can bring alcohol or not, people can bring other children if they need to, they can come and go.
I'm saying that sometimes if these things aren't working as you'd hoped, it might be worth thinking about it from the perspective of those you've invited, and thinking why they might not be willing/able to accept the invitation.