Earlier quoted context omitted.
If you disable Javascript, it seems to still load the full article, and doesn't break formatting.
Plus if you're decent with the inspector, you can usually remove the paywall and then if the body doesn't scroll find the Event Listener for `onscroll` and kill that; it almost always is just a simple fn preventing scroll events
On this National Geographics page, in the inspector just select the and in the CSS pane remove the "position: fixed" and "overflow: hidden". This allows scrolling.