Learning Plan Status - Remain in User History?

Summary

Assign LP by dynamic group but don't want to add new users. Still want LP in history

Content

If I assign a LP using dynamic groups bit I don't want the learning plan to continue to be assigned (after specific date), should I no longer assign by dynamic groups?  Or just make a copy of a dynamic group and assign that way?

Or is there a way to stop the dynamic groups from adding more users?  I hate that the LP will no longer appear on a learner's history!  They will be so confused.

Does anyone have a work-around??