Moth3r - it's not as painstakingly difficult to do as you would think, as I would only be restoring the non special edition shots to a higher quality, not the whole film. Doing a whole film this way would be impractical, but doing the non special edition shots, that's easy enough.
I would not be using shots where the camera pans. That would be impossible to sync up, and the motion blur would remove most of the positives of the larger pan & scan transfer. Widescreen will do fine in these cases.
I had very good luck with superimposing pan & scan images over widescreen images when doing restorations for Deleted Magic and things ... and superimposing laserdisc over DVD images and vice versa. It does seem that because of the nature of film, if the most important part of the shot, that the eye is really looking at, is made at a higher quality, the quality level of the entire shot raises dramatically.