@HannahS
Is there an option to reduce to a free plan but not lose all the board content?
Yes, you can cancel your subscription, which will downgrade you to the free plan.
Does this content stay accessible but not editable?
Yes and no. You will still have view-only access to all boards.
However, any custom templates you have created will no longer be available or accessible. You should copy of of them to one or more boards should you need to view them.
Also, any Projects you created can no longer be modified or deleted.
Can team create any new boards?
Yes. However, only the 3 most recently created boards will be editable as this is a limitation of the Free Plan.
One more note on downgrading from paid to free: Any boards that are currently “private”, i.e., the team-level access is set to “No access” will show as “LOCKED” and will need to have their team-level access set back to “Can edit/view/or comment”. More on this here.