I keep some potted brugs in the house overwinter, and some go into the unheated garage.
On the garage ones, last year I had one drop its leaves and the other one didn't. Funny - there is no window in there, just light when I open the door.
This year I have 2 brugs that are still in the ground. I am wondering if I should dig them up and pot up now, or wait until a light frost makes them drop their leaves. They will then go into the garage.