As a rule of thumb, I stop heavy watering after new growth has stopped growing or slowed a lot.
For me thay happens after the first cool front moves in.
I continue to give Cattleya light and will water once a week.
As the temps drop I move all but the resting Dends into the GH.
I only move in to protect from freezing temps.
By spring all leaves are gone but flower buds will develope at the nodes.
I hold water until new growth apears.
Some folks hate to not water thier orchids, just think of them as decidious trees that lose leaves in fall and grow new growth in spring.
This is what the work is all about
:
IOSPE PHOTOS
Good luck