I would not head back to ANC on the 2nd. I'd stay on the Kenai for another day, and either do a glacier cruise out of Whittier (Phillips or Major Marine), or go down to Homer. (Bald eagle capital of the world, and halibut capital of the world. Worth the drive just for the fish tacos at Lands End.)
Kayaking in Resurrection Bay while in Seward is really great, if you like outdoors activity. We and our teenage kids loved it.