Don't know on the N model. Not to complicate things, but on the standard model, the tire chosen effects over all width to a degree. Over all width must apply to the outside edge of rear tire to outside edge of other rear tire. That is the width distance on the tractor.
The N (narrow) is great for vines and orchards, but doesn't or wouldn't work for us in the vegetable field. We straddle rows. Your methods maybe different. I know a lot of folks who use bedders and double wide plant and run their tractors down between these double wide rows. An N would work for them. We single row plant @ 40 inches.
I might also say that while 75% of the purpose of the tractor is in the garden fields, there is that 25% of general stuff too. Hauling wood, shagging logs, moving manure, gravel, sand and other product. We also have to plow snow, so the tractor had to have more versatility or utility then I would have preferred. Hope that makes sense. So, I ordered a front end loader, which is a must for us now. I also ordered R4 industrial tires, which are too wide, really. Ag tires would have been superior, if this tractor was a dedicated garden tractor. But, it is not, so compromises had to be made for puncture resistance in the woods.
I'm guessing here, but overall width is effected by 3 or 4 inches by tire choice.