The strongest part about this manipulation is that you have certainly conveyed the idea of "cold". Looking at this piece just gives me the chills. The coloration of the background and the model truly makes this look like a winter scene. The snow wasn't overdone, either.
The blending is fantastic; the background looks to be a very cohesive whole rather than being separate images put together. Everything just fits.
There are just a couple of suggestions that I have. The first is to have the model cast more of a shadow. Since the light is so strong behind her, the ground should be darker in front of her. I can see the reflection of her figure in the water, but the reflection actually brightens the ground right at her feet. It would be best to brighten the sand on either side of that reflection and darken the area the reflection covers.
The second suggestion is to lower the brightness level of the sky - not by much, but just a bit. It looks a little overexposed. As a result, it's a little distracting. My eyes were drawn to the sky first instead of the model and the foreground.
I hope this has helped you in any way. This is a beautiful work, and these suggestions are minor. You have done a great job.