I can't speak to the use of triple thick, but I'd highly recommend you remove the backglass if it is going to get near or below freezing where your machine is kept.
As an example, I kept an older pin in my garage over the winter (in the Midwest) several years back that I was not using and left the backglass in place. When spring came, I turned it on and tested the machine. I found that it worked 100% without any issues in function or appearance. However, the backglass wasn't as lucky. Apparently, the art fully separated from the glass and effectively turned into many, many pieces. Only 10% of the art remained.
If I only took this piece off and stored it in the house, the machine would be have remained perfect. Lesson learned.