Change size of all threaded text frames to match new margins

Hi all-

I have a 200 page document with threaded text frames of the same size on every page, and decided to shift the top and bottom margins to make the text space smaller than when I started, so now I obviously need to shift the 200-page threaded text frames to fit the new margins. Is there a faster way to do this than having to individually resize all the text frames on each page? It looks like the old Automatic Layout Adjustment feature would have helped, but I can't find it in InDesign anymore (InDesign 2021) even though the user guide still seems to reference it. And Adjust Layout doesn't seem to do anything (and reading about Adjust Layout... doesn't seem to be what I want).

https://helpx.adobe.com/in/indesign/using/adjust-layout.html

Thanks!