Well, we finally got our first frost here in southern Oregon, on December frigging 3rd, wow, the climate is just odd these last years. We keep our Flytraps outdoors until it is almost frost/freeze and then bring them into greenhouses and keep them at around 50F.
For “dormancy” the most important thing is the plant’s exposure to the changing light cycles, this triggers the Venus Flytrap to go into dormancy. Venus Flytraps, like other species like trees and bears, like a nice winter rest so they can spring back in the Spring. Cool temperatures also help, but the outdoors light cycles are integral. So, if it’s frost/freeze where you are, be sure your Flytraps are in the windowsill that gets the very best light and sunlight, and then put them back outdoors when the weather allows!
Nighty night little traps!