I leaned on …hubpages.com/…/Drag-Force-and-the-Terminal-Veloc…
and specifically:
…saymedia-content.com/…/drag-force-and-the-termin…
I estimated the area of a body in vertical position as 1/4 of a body in horizontal position.
With C going from 1 to 0.7 and A going from whatever to 1/4 of that, this results in a terminal velocity increase of over factor 2.