Print size restrictions are determined by the printer driver. The printer driver is accessed through the Page Setup button in the lower left-hand corner of the print module.
The issue is Photoshop has print length limits of about 91 inches and you either need a second party RIP to print longer prints on a roll. I think this is related to Windows limits as well. Have you or anyone you know of printed 96" as a single print on a roll of paper? I saw a post when searching this AM where a person talked about printing longer than the usual limits through Lightroom. I'm using Windows 7, have the CS6 Master Collection and Lightroom 6. I'm trying to see if there are any people who have actually done this and have set up info before I waste paper and ink printing out truncated prints. I've been through this years ago and am trying to see if anyone has full info for doing this process with the latest software - and if perhaps Lightroom 6 can print this without any special adaptations. Thanks!