Separation anxiety & leaving for first time

So we have a wedding come June. It’s 4 hours away, and starts at 4pm. My daughter will be 8.5 months. Atm she’s been going through crazy bad separation anxiety.. she’ll be staying with my parents. My mom is nervous, as this little girl chokes and hyperventilates a bit when she cries too hard. So we’re all a little worried about her. We plan on doing a trial day or two before that to see how it will be, with both us 10 minutes away just incase! Any tips, tricks?

She’s nursed to sleep, but she used to take a bottle good (she’ll have to that day so..) but worried bout nap time, bedtime, her waking up and looking for momma...

Anything we can do to help her? And me? Lol very nervous first time mama.