The whole point of an orthographic view is the distance from the camera doesn't affect the size. You could try scaling the layer/layout instead.
That does not fix my issue it seems. Also the orthographic view does not fit the preview window despite being on letterbox scale. I get the point is that distance does not affect the size and that is the desired result. so that objects maybe behind a wall on the corner won't be obscured by it's relative perspective. But not being able to choose the orthographic scale limits it's usefulness.
Blender has a orthographic scale option in it's camera settings. could something like that be added to the 3d camera object?