Looking to resize pages, and all content in pages to remain in same proportion. Is there a way to do this?
Indesign has Alternate Layout options, such as Liquid Layout. These are used for designing content for different digital and print mediums.
Adobe has an overview of this workflow here. https://helpx.adobe.com/indesign/using/alternate-layouts-liquid-layouts.html
Read up on these alternate/liquid layouts, as they're probably your best bet.