Saving breastmilk for high risk events

Hi! I’m currently in the process of stopping breastfeeding.

In 3 weeks time, we will be going on a short overseas trip via flight. And in 4 weeks time, my baby will be attending a party with many friends and relatives. Ive read that breastmilk essentially coats the entry points and minimises the risks of viral infections.

With this in mind, should i freeze whatever milk i am pumping during this weaning period and feed her said frozen milk throughout the trip and before and during the party? Is this scientifically sound? Or should i just feed whatever ive pumped now.

Thanks in advance!