Easiest way to tell is by level. If you’re level 12, then you’re ready to finish the game and won’t be far of being able to do so. That’s the best way to guess time left, spoiler free. I’ve completed a run in 30 something hours, and I’ve got one that is like 60+ hours long with ages to go.
As someone with two young children, I find playing with childless friends much faster as they can be flexible and play when i find free time than with childed friends on set weekly scheduled.