Reasonable on 05 November 2011
As ever it depends on the game assets and their quality. LA Noire simply had more assets and generally they were of a higher quality than GTA IV. RDR was actually (and sensibly) a fairly barren place with a lot more open countryside (which requires less assets as they clearly repeated lots of trees, bushes, etc) so it was never going to need a ton of space.
Of course, if they do ramp up the asset quality and quantity or aim for LA Noire level mocap and performances then the game will quickly spill over to 2 or more DVDs.
Try to be reasonable... its easier than you think...
