There is no way easy way to do it in InDesign that I know of.
At the company where I work, we sometimes do books and they end up being printed in two different sizes. The first one at 100 percent and the second at 115 percent.
What we do is keep the same file. For the 115 percent one, we make the PDF, open it in PitStop and change the size there (the 115 percent). And then (while still in PitStop), remove old cropmarks and put in new ones at the new margins.
With the number of books we do it would be a logistical nightmare to make PDFs of all the pages from the 100% file and import as PDFs into a different document for the larger one.