The device seems to work for cold weather. I have a Samsung S9+ in an otterbox case. It barely fits. I'm not going to take my phone out of the case everyday. I suggest an XXL option.
Love the PHOOZY!! I took this skiing this week and it really helped with battery life. Plus it kept the phone dry. The extra padding for my regular falls helps too. Sleek design that allows my iPhone 6 to slide easy in and out.