I'm a little late to this particular discussion but I'm not convinced CDPR would delay the game.
I personally think The Witcher 2 was rushed at the end too. The first couple of acts were 15 hours each and had large open areas with lots of quests. The last act was only about 3 hours long, it took place inside one city (no exploration), the map had loads of invisible walls, ARPG gameplay and it was cutscene heavy with a rushed conclusion. Now it's possible this was their vision of the game all along, but I do believe they ran out of time and had to release it to meet their deadline. I think the enhanced edition later added some content to act 3 to fill it out a bit.
This is one of the reasons I actually prefer the first Witcher game to the second one. I don't think CDPR has the luxury of going for a 'when it's done' approach. Especially since they are in the habit of adding more content later. It's a bit of a shame that the best way to experience a CDPR game is a year late when they've released the enhanced edition.