Rule of Thumb?

[bpeder]

Answers to my question might be helpful to those of us in the large format graphics reproduction industry. We are often asked to create single page large format prints of complex MS Project Gantt charts. Most customers want the fonts to be in the 11-12 point or legible range. Is there a rule of thumb that would help prepress technicians who have less MS Project savvy to decide quickly and dependably on a custom page size to distill their PDF to? For example: "If a Project file distills to "X" number of letter size PDFs, distill a single PDF with a custom postscript page size of "X x Y"..." Right now I have to save and soft proof multiple PDFs before we get a file that will force all the data from the Gantt chart into a single page with reasonable font sizes. Then we might also end up dealing with too much blank space, or a PDF that is scrunched into portrait orientation when landscape would be better. Thanks.