Find a good agent and you can always get a seat. I just got two for THIS June to Athens. This was a couple of weeks ago. A few agents swore they had nothing. You just have to call like 20 times. 90% of them are morons but the 10% that will take the time to help you can find you a seat anywhere, anytime. You just have to be patient. Why Delta makes it most loyal customers spend 20 hours on the phone is beyond me... (not to mention tying up its agents).