On the other hand, an offset of only 3/4" or so really improves the transition from tangent-to-curve both aesthetically and operationally, while effectively adding no more than 1-1/2" to the width required for installation. I think you would have to increase the diameter of a fixed-radius curve significantly more than that to achieve the same operational result, and would still miss the improved appearance of an eased transition.
Not to be the odd guy out, but I think you would be better off going to a slightly larger radius. Spiral easements take up room that could be used to make the circle bigger - stated another way, with a given space, an easement will force the final curve to be tighter.