Re-use/reschedule of dripped course

Let's say I have a course with dripped content that:
- I want to run multiple times each year
- and I want students that have completed the course to retain access to the lessons

What's the right way to facilitate this?

My initial idea is that there's a master course which has the dates rescheduled each time, then a duplicate of it (ugh) that past students are enrolled into upon course completion.

However.... is it a possibility that once a student has completed the master scheduled course, then they're able to retain access to all the lessons even if the lessons are rescheduled to later dates?