Acrobat and Word refuse to export .docx to bigger than 20MB

First things first.

Mac Pro (late 2013) with El Capitan 10.11.6, Word 15.24 and Acrobat Pro 2015.017.20053

I knocked together a Word document which happens to have a lot of images. It needs to go to some legal people (et al) so I wanted it in PDF.

Within Word it fails with a message:

"This version of Word can't export to this type of file because the file is too large. Generally a file that is larger than 20MB is too big to export"

Unimpressed with this arbitrary cap on file sizes and also the hint that there might be an unspecified version of Word that does work, I tried Acrobat.

But Acrobat uses Word to do the export. It fails with the same message. What is the point of that?

How, good people, short of wasting hours of my short life resizing and replacing masses of images can this absurd restriction be overcome?

Many thanks,