At the moment i have two Coryanthes with buds and they are growing at a "normal" speed. The day temp is about 18C ,at night it goes down to about 10C.
The buds seem ok for the time being, but i am not certain if it will be too cold for them. I am very careful when i water them so only the roots are moist, new shoots are growing as expected.
I cant afford to heat my growing area as much as i would like this winther, but hopefylly i will see some flowers in a few weeks.
( I also have a lot of Vandas and Catasetinas in the same area and i have five Vandas in bloom and buds on three of my Catasetinas
)