(I'm reposting this as an "Answer" because a bug is preventing "Comments" from displaying sometimes.)
@xose is right about snow and ice making exposure tricky. The glare from an ice surface can also be a problem with exposure, but that will be major issue only when the camera is pointed toward the sun. If possible, the camera should be set up to the south of the subject so the sun is behind the camera most of the time. If that is not possible, it will be hard to ensure that photos taken into the sun will capture much useful information. This is an even greater issue in winter when the sun is low and might be captured in the photo frame causing lens flare in addition to under exposure of everything else in the scene.
As soon as snow covers the frozen water, glare will not be a problem, and the exposure issues that Xose described will be more important. If glare from an ice surface is a persistent issue, a polarizing filter in front of the lens can eliminate it completely.