Yes, this is probably the “easiest” option…you’ll also have to drag across Inserts and copy sends too onto the new Mono Track(s). Might be worth putting in a request on the Cubasis forum for an option to Export the song files as is and not turn Audio tracks into Stereo ones. Lars, the Steinberg employee over there answers most questions so I’m sure he’ll at least say something.
FWIW, in my experience even ignoring Mono/Stereo differences the projects never sound the same…not a major issue for me as the iPad is only for use as a sketch pad but I suppose it would be good if it all came across identical!