Can you still pre-order the DDE card and get it by mail? That's how it worked last time I got one, and I'd prefer to do it the same way rather than buying it once I arrive.
Yes you can, you just need to make sure you order it in time to receive the card. I think you still have to fax in the order, not sure if it can be processed by phone. You can download the form from the passholder site. FWIW.