If I downgrade, what will happen to projects with more than 5 collaborators?

If you are not the project owner then you may find a project is archived if the owner of that project has not continued their Business subscription and the project is not within their free project allowance.

If the project is not within the free projects allowance, then the project will be archived and the owner and the first 5 collaborators will only be able to view the project in a read-only format.

Any additional collaborators exceeding 5 will find the project automatically archived and will also be locked out of the project – they won’t have access to any of its tasks or data of any kind.