How to convert an 8x11 document to 11x14 in InDesign

I've set up a 8x11 poster. Then at the last minute they also want it in 11x14. We're basically just emailing the posters as PDFs and folks can download it and then print it off of their local Xerox machine (no professional printing).

After version 1 was ready I was going to save a copy and then change dimensions to 11x14 then move everything around but there just seems to be an easier way to do this. Because the PDF is print-quality I'm even thinking just send the 8x11 to the printer but tell it to print on 11x14 but prefer just to set it up at the size they want.

Is there any easier way to do this in ID 2017 CC than how I plan to do it?

Thanks.

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