I know it sounds crazy, but I'm still hoping we trade him before this season gets going... Trading him at the deadline would be pretty foolish, as you have stated above, but if we want to max out the haul, trading him now, with 2 years left before free agency seems to be the wise thing to do. If we wait until this off season, and he only has one year left, we won't be getting nearly the haul we would get now. imo
All it would take is for one of the big time contenders to lose a big arm due to injury in spring training. Teams would come calling if they need a starter, and that is when it's time to take what we can get in a major haul!