It's not possible at a user level, however I would strongly suggest going with the role based approach anyway. It is far easier to manage, because I would (if I bet) put money on someone else needing that in the future.
Completely agree with Andy on this. In addition to additional users needing this functionality you should also consider if the person left the organisation. You would then need to add the additional privileges to the person who takes over etc.
Best practice is to use Roles to control rights.