Create Distance Based Bike Workout

Is it possible to create a distance-based bike workout, rather than a time-based workout?

I created a time-based workout for climbing Alpe du Zwift (Road to Sky Route), see: Free Custom Workout for Everest Challenge: Alpe Du Zwift Endurance Climb
It works pretty well but would be better if I were able to create a workout based on the distance for this rather than time, as changes in my FTP and/or weight change the timing as well as unforeseen circumstances, such as technical or other issues that make me go off the bike temporarily during a workout.

any how to create a distance based cycling workout zwift?