DL applies KE blackout dates across the board. DL also has blackout dates for CI, and they apply as follows:

01JUN 11 THROUGH 31AUG 11
10DEC 11 THROUGH 31DEC 11
01JAN 12 THROUGH 04JAN 12
16JAN 12 THROUGH 26JAN 12
01JUN 12 THROUGH 31AUG 12
10DEC 12 THROUGH 31DEC 12
01JAN 13 THROUGH 04JAN 13

Thus, I'd stay on the flight you've got. You have a J seat at low mileage, presumably without fuel surcharges. Looks like MU would be the only alternative, but that's going to involve way more flying than just taking the non-stop, and EF isn't showing any MU business award availability in the next couple weeks for that route.