Either would be fine at this age, they sleep so much that it wouldn't really matter. The only issue I'd see with driving is that it's not good for their backs to be in a car seat for extended periods at a time. Planes have little bassinets for babies so just make sure you get a seat with one. With the ear popping thing, just make sure she's being fed or has a dummy during take off & landing, the sucking helps so she should be ok.