I am in a townhouse with an entirely internal bathroom. We have a conventional extractor fan that does not prevent mirror fogging and general dampness.
We have stopped using the extractor fan in favour of running a portable desiccant dehumidifier just while showering and drying off. This is far more effective – no more mirror fogging and much less overnight condensation on windows elsewhere in our unit. It consumes about 730W, which, in a small room, is enough to also be useful warming in a Canberra winter. Without the fan running, that heat stays in the room.