...I'd really love it if there were longer rides for endurance riding rather than shorter climby stuff ... Even if a 100mile 'ride' was split into 4 sections ...
Veloreality does that. They have many rides that are few hundred km long, rides like Grand Alps, Gaspe are more then 600km each. They're made of many separate videos each but the software can stitch them on the fly. As the software keeps the current state of each ride as you progress you can do multi-day riding.