We are leaving on January 4th. I'm afraid that my daughter might get an ear infection before we leave. Can we give her antibiotics as a preventative measure?

It is not recommended to give antibiotics as a preventive measure in the case of ear infections. This could increase the risk of your daughter developing resistance to commonly used antibiotics. Instead, it is suggested to use a nasal aspirator or Sinus Rinse™ (depending on her age) twice a day until your departure. Additionally, try to ensure she gets enough quality sleep leading up to the trip.