I'm facing this challenge with my personal portfolio: how to make a long case study more digestible to compensate for too much content that causes a lot of vertical scrolling.
Current website prototype: https://daniel-portfolio.netlify.com/case/blacktrax-website
One of the my ideas is to use another navigation layer for case study subsections. Either as a side navigation or a top nav sub-navigation.
References: Bootstrap 4 http://getbootstrap.com/docs/3.3/css/#tables-contextual-classes
Smartisan OS https://www.smartisan.com/os/#/powerful
Smartisan OS-6 https://www.smartisan.com/os/#/6-x