Restore Structure Only We have a database that is 3TB+ in size, and don't have enough space to restore it.

However, we want to retrieve code (stored procs) from a 15 day old backup.

Is is possible to restore the structure only from an Oracle backup?
The source of stored procedures is stored in the SYSTEM tablespace in the SOURCE$ table. 

You need not to restore any user data at all, simply restore the SYSTEM, SYSAUX and UNDO tablespaces and skip the rest. You can then open the database with the other tablespaces offlined, and you can access the stored procedures as usual, or query DBA_SOURCE or SOURCE$ directly.