Include same page by default that could be later updated across all subsites?

Just wonder if something like this is possible?
All the subsites are created from a template site using “new blog templates” plugin and they all have the same pages by default.

The pages are not editable by users(they only make blog posts) but I would like to eventually update all those pages across all the subsites that were subsequently created.

I see alot of posts about how to include content from one page to another based on page ID using a shortcodee added to functions.php. BUT, I need to them all to pull the conent from the same page in my default template site. This way if I needed to add content or update a page I could update the one page which would also update the same page in all my subsites.

Like if I used an iframe I could then just update my template site and all my subsites would be updated. But I figured that may not be responsive and not sure if the shortcodes would work?

Does that make sense? I want to have a couple pages in ALL my subsites with the same duplicated info that could be easily updated at a later date.

thanks!