Perhaps I can add a bit of perspective to this.
I work in the film industry and, years ago as something of a beginner to postproduction, I was involved in test and development for a colour grading system, as part of which I helped build two colour grading systems and install them at a studio you'd have heard of in Los Angeles. The new gear was intended for use in their remastering section. On the day we were there, they were putting together a cinerama movie, using the grading gear to remove the visible evidence of the join lines. The three 35mm scans formed an image more than 6K wide and of course, it looked absolutely spectacular as an uncompressed DPX sequence. I don't remember what the film was, unfortunately, other than that it was a western.
How The West Was Won, it's a very nice blu ray.