Especially if it is 1 frame wide, they don't have the area to cluster and keep warm when outside. If you go with more than 1 frame wide that will improve thier chances, but also decrease the ability to watch what goes on in there.
I keep mine in my den, and it is worth watching all winter long. I've only had about 5 bees loose in 3 years. And that is with 5 kids under the age of 12.
Although I did end up with a quart of 2:1 syrup with HBH smashed on the carpet
But that is another story...