Anyone that fights at 168 would go up to 175 to get a fight with Bhop. I think that he is more likely to move up to cruiser to fight Tarver.
Hopkins was 186lbs went he stepped in against Pascal so it seems unlikely he could make 168lbs, he has developed into a solid light heavyweight now. I don't think he'd even meet them at a catch weight now either, any supermiddle is going to have to move up to 175lbs if they wish to face Hopkins.
I think you already know the answer to this, the guy is pushing his luck fighting young guns as it is, facing a fighter who has good stamina and with the scenario where he has to lose weight that is by now most likely muscle will not bode well for him, then again Hopkins is one of a kind.
Can't make it anymore I'm afraid. The man is in superb physical condition still but those pounds taken would also take the health to make him fight strong and sharp. There's a reason why all those guys, Wright, Calzaghe, Pavlik, Ornelas had to go up to 168 plus. Old Man River would not be the same to come down in weight after he went up there to fight Tarver.
It is only three years since Hopkins did 170. And I won't quickly forget Hopkins doing 156 with relative ease for Oscar in 2004. I agree that he'd likely come unstuck if he tried it, but I wouldn't ever write him off to be honest.