Night temperature for parvis?

[squashcat]

Hi everyone! I am trying my hand at some parvis; I recently acquired paph. delenatii, micranthum, and Magic Lantern.

I know these plants need to get cool at night to initiate flowering. What I need to know is, how cool is cool enough? If they need to get below about 67 degrees F, I'll need to move them out of the growing area at night to a windowsill or something. Or is it based on an average temperature drop, like phals?