How wide a clearing path do I actually need?

A 24-inch path is plenty for one- to two-car driveways. 28 inches starts to make sense once your driveway is longer than ~60 feet or wider than two cars. 30–32 inch machines (like the Honda HSS1332) are heavy, expensive, and overkill unless you're clearing a very long rural driveway or routinely dealing with deep snow.