My syndicate are pondering an electrical hookup and dehumidifier for our trailer that's kept over winter at a site that's humid and cold (it's probably in cloud for 50% of the winter).

The trailer is an older metal trailer with unsealed doors and a rotating air vent.

I'm wondering how effective a dehumidifier can be in these conditions? It is possible to reduce the humidity in a non-sealed trailer or do you end up trying to dehumidify the world's atmosphere what with relative humidity and equilibrium as it is?