I came across these two pieces that I had started a few years ago (see posts on 24 November 2013 and 29 November 2015).
For the first one I thought I would use Antwerp blue for the sky and the ice covered lake.

Frozen Lake 2
I added burnt sienna to the blue and painted in the trees on the far side of the lake and set it aside to dry.
For the next painting I used French ultramarine blue for the sky and the shadows on the snow covered lake.

Cold and Calm 1
I used burnt sienna and the blue and painted in the rocks in the foreground and on the far shore.
I will post each of these paintings at a later date once I have put in the pine trees.