i'm applying this year and figuring i'm going to get screwed up the wazzo on plane tickets.
i'm sure if you wanted to, you could postpone interviews until a date, say, in february, but remember that most (if not all) of the med schools admit on a rolling basis. the longer you wait, the less seats there are available that you're applying for.
if there's one thing i think everyone would agree on, it's that the earlier you can get things done, the better off you are.