Maybe it would have taken them a year and a half. Though I think the problem would be balancing, seeing as how they would have to change the gameplay to something else and then see how they would balance the missions.This really disappoints me. I'm vapid with gamers and think that 358/2 Days in its current form but with HD graphics would have made it a better game (and some elements would have been automatically approved due to no hardware limitations, like the backpack.)
I really wonder just how much effort a HD version of 358/2 Days and Re:coded would have taken, due to the year difference in release, them making the cutscenes, and re-using assets that are a decade old. And I wonder, if they hadn't pursued the PS3 remasters, if it would have been possible if they aimed for the PS4 in the first place.