What is the theme in the poem "Stopping by Woods on a Snowy Evening" b by Robert Frost?

Stopping by the Woods is about death. How come, he is riding his horse and he knows he is not going to come back. Winter represents death because its near the end of the year.

The narrator knows he is going to die and he is okay with it. He takes it slow while riding and takes in the scenery. Its a depressing poem but Robert Frost is very intelligent in the way he writes his poems