Good morning;
The Kiev SLR camera in its many forms, Salyut, 88, 88CM, and others, is an interesting camera. There are so many things where you wonder; "Is there really a problem, or is it just being a Kiev-88?" I do have a couple of backs where it was necessary to take them apart and reshape the latch to allow the little button to move enough to release the back from the camera body. This was at normal room temperature.
As far as it getting cold, it was intended for use in Siberia also, and it is rated for use down to -15 degrees Celcius, a weather condition that it likely would encounter. With special consideration for very cold weather use and lubrication, it can go lower, but then you also start to encounter static electricity effects with the film itself.