Real Florida's citrus farms are inland. Leonida's are inland too. Orange groves can be seen in aerial shots in Trailer 2 - one of the clearest pieces of agricultural detail in the trailer.
See the rural towns piece for the entire rural area.
What's visible
Rows upon rows of trees planted in even intervals. Enclosed fields. Service roads weaving through them. The aerial framing makes it clear: orange groves. No other crop would have that colour and planting distance.
It's unclear how big the citrus belt is. From trailer aerial views, it seems to be a substantial inland area, but not one that dominates everything.
What this region is likely to do
Ambience, primarily. Long stretches of quiet country roads. Potentially a story location for a hideout or meeting spot. Wildlife encounter territory. Low-to-medium side content density - this is the type of area Rockstar creates for mood rather than for gameplay loops.