How many guests stay for send off?

I'm planning as if 100% of my guests will stay. I'd rather have too much than not enough.

Additionally, my venue closes at 9, so I think that even the older crowd, like our parents, will hang around since it's not too late.

We’re doing our send off between the ceremony and reception rather than at night. Our hotel is attached to the reception so we thought it might be odd to “send us off” around the corner lol but I am planning for 100% if my invited list. I second the id rather have too many than not enough

Thanks, ladies. I was thinking 100% as well, I was totally thrown when it said half your guest list!

We didn't do a sendoff but we did do a late night snack, and our venue budgeted for 60% of guests to still be around at 11 with the wedding ending at 12:30. this was probably about right in our case, maybe closer to 65-70% though.

We bought enough glow sticks for everyone, our wedding ended at 10 but most people left around 9:30, (it was an hour drive for almost everyone not staying at the hotel) we had 65 guests and about 25-30 people left for the exit