"increasing darkness on the face of the deep." is not clear to me to what deep refers to. I think of the sea,or perhaps the sky.
I am new at reviewing so it may be over my head, or you may have meant to leave it up to the reader.
"Promised hope held in this symbolism teaches the lesson of Nature's baptism.'
is a beautiful line, but I am a bit thrown off by it.
I am not sure what the baptism is referring to.
Once again it may be me. Winter brings out a sense of nature hibernating and I am not sure of that imagery and baptism in the same line.
It works for me anyway, but it made me stop.
The imagery of the Phoenix reminds me of spring, so I think of Winter enabling the spring as the Phoenix. I love the imagery. I wonder if it should be the last line.
"Wondrous this message that came from afar,brought by magicians that followed a star."
This imagery sounds like a reference to Christmas, and not Winter to me.
The overall impression of the poem evokes a lot of imagery.
I love the first four lines.
Overall, my feeling is that the images came to me independently more than they flowed together. I did like it very much.