Thank you very much for your reply! I will try Delta tomorrow night (331 days, right?) for the outgoing flight, but what do I do with the return flight? Should I just wait a week? How does it work? How difficult is it to book GCM in June (4 tickets)? Should I try both airlines and cancel one? Can I cancel without penalty? Should I call customer service or book online?

I have many, many questions and very little time!