Keep in mind that all my 1000+ tropical plants are outside, from around April 1 till November 1. They are all under trees (except the Plumeria, which take full sun). Even though the "mother" fiddle as well as her siblings and the seedlings are under these trees, getting some early morning or very late afternoon sun, they get watered along with everything else that's outside, and unless we get a good rain, I water practically every single day, with copious amounts of water. I assure you, NJ is no where near as humid as MS is.
When the weather begins to get around 60 F (at night), I begin to bring the plants in. I'll begin with the more cold-sensitive plants, such as orchids, progressing to the more cold-hardy plants, such as the ficus, bromeliads, plumeria, and staghorn ferns. The move-in generally will be over a span of 2-4 weeks. When my fiddles are inside, the watering frequency will be reduced. I just look at the soil and if it looks dry, they get watered. There is no specific schedule for watering. I still water copiously, wanting water to flow out those drainage holes. Actually, for those fiddles inside the house over the fall and winter months, with central AC/heat, there will be little humidity for them, so I spray/mist their leaves every few days to help raise the humidity, at least for a short time. There also won't be the heat and won't be the air-movement that they'll get when outside. Thus their need for less frequent watering. They also will go semi-dormant, and won't need as much water because their growth will slow a bit.
If I had to choose a spot with more humidity or more bright light, I will always choose the bright light. Fiddle leaf ficus are trees in nature and thus, when inside, they flourish in bright light and sulk when there is low light.
