This is a case where I would look into renting HD software(check the avid store for this) for a month. While you ARE able to open the complete sessions, create stem mixes of sections of the orchestra so you can create new versions with the original tracks made inactive so you can get things down to a manageable number of active tracks
BTW, the rental of an HD iLok asset is all you need. With that on your iLok, your current install will open as HD software.