Hi, Frank:
I have no idea whether this is even possible. PDF files are in a proprietary form and my understanding of how ODS PDF works (conceptually) is that your output is formatted in some buffer area as though it was going to a physical printer and then that internal copy of the printer version of the file is sent to PDF proprietary format. So I don't know whether the Adobe proprietary format that ODS creates has that capability to switch orientations in midstream. My assumption is that if it were possible, the developers would have implemented the capability for PDF at the same time, or shortly after, they implemented it for RTF.
If you send a mail to ods@sas.com, you could ask the ODS developers whether it's a possibility or not.
cynthia