babies travel more comfortable than us. if your concern about the ear pressure, you can try giving your baby some milk at that time. it can help reduce the pressure.
but good that you decided to go in summer cause i had a talk with a patient's mother before, she said she brought her 1 month old baby during winter time, baby came back with lung infections and unfortunately died. (( didnt see the baby's casenote. dont know if its caused by the cold weather.