Shooting after dark means you need to take safety seriously. An essential item of kit is a head torch. If possible, pack one with a red light as this won’t affect your night vision as much as a white LED light would.
To avoid knocking the camera, use a remote-release cable or a radio trigger. The camera’s self-timer mode will also allow time for any vibrations to dampen before triggering the shutter.
With long-exposure times, you will need a tripod to capture a sharp image. Temperatures will be cold, so either use a tripod with foam surround on the leg sections or add some DIY foam yourself to save your hands from freezing.