I think there are a few of those he can't win. I think the final kilometer in Strade is too steep for him (assuming he doesn't arrive solo), don't forget he isn't even the best climber of the crossers. Can't see him win FW either. Lombardia? San Sebastian? LBL?A better question would be which one he can't win. I don't think there are a lot of big 1 day races that he is incapable of winning.
Other than that, he can probably win anything. And obvisously i mean in "normal" conditions. Ofcourse if some freak scenario unfolds, like how Van Avermaet won the Olympics, anything is possible.