I would still try to trade him if at all possible. If we aren't going to get good value, then I am fine with playing hardball. He wants an extension, or he wants to hold out? Good luck buddy, we hold all of the power here. Given previous tweets, the cowboys locker room fiasco --- and his passive aggressive stance towards a few teammates, I think it is safe to say that he has mentally checked out long ago.
If he wants to hold out, I say let him. When he holds out for long enough, and the league bleeds him dry with penalties he will come running back. We could even drag this out with the franchise tag if he wants to be difficult. The Seahawks, and Pete Carroll need to assert their dominance here. We shouldn't trade him for mere scraps, and we also shouldn't just cave in and give him what he wants if he is being unreasonable.
Earl Thomas can't afford to play a war of attrition with the Seahawks. If we do end up trading him, I sincerely hope that he goes to the Cleveland Browns. Both out of spite, and the prospect of having an advantageous spot in the draft.