A very reasonable assumption, but unfortunately I wasn't being as clear as I should have been. While we could probably pick a different departure day if we HAD to (e.g., if there wasn't even a coach seat available), given that we can get from NYC-xMIA-SCL, albeit in coach, I think we'll stick with that departure.

On the LIM connection, I actually had reserved seats on that, and was later told that the reservation was improper because Lima and Santiago are in different regions of South America, and I wasn't allowed to touch down in both regions. But maybe it's worth arguing with them further over that...