I really love your colour scheme. Already this has a great mood. The curvature you've got on this is probably very intentional, but I think it will make perspective much more difficult to tame as anything that is slightly off will really show. Maybe trying it first with a straight horizon line would help? At the moment, to me the reflection looks more like an iceberg rising up out of a pool of water. I would vertically mirror the top half, maybe with some adjustments to the height to account for the angle, giving the reflection a lighter colour closer to that of the ice on the ground, and getting lighter as it reaches the top (or bottom now) of the ice so that it blends in with the ground more.
[EDIT] looking at it more I can see that the "ground" may actually be water, which also works. At a glance though the reflection of the ice to me looks like a pool of deep water surrounded by an icy ground.