I don't get why their milking the Snowman!
The ending;
The story ends after the return journey. However, the sun has come out the next morning and the boy wakes up to find the snowman has melted. The boy begins to wonder if the night's events were all a dream, but he discovers that he still has the snowman scarf given to him by Father Christmas. Realising the night's events were real, as the credits play, the boy mourns the loss of his friend.
Why would he then re-create the Snowman years later and a Snowdog to also met the same fate.