It seems like the stickers on the back of my sensors (http://suretydiy.com/product/2gig-thin-doorwindow-contact/) are having a hard time with the cold. Do you know if these can be screwed into the wall/door they are attached to or should I consider some sort of epoxy to secure them better?
The sensor itself can be screwed down, but the accompanying magnet is not designed to do so. If you open the sensor you will see screw locations. The best alternatives for an adhesive varies based on the climate of your service address. An alternative is to utilize a different magnet that can be screwed down as well (we offer these, which have back removable back plates with openings for screws.
These are two things I have on my dw10 sensors
Double sided sticky tape from Lowes (3M/Scotch) stronger adhesive