What my son likes the most with winter is making a snowman.
What my son hates the most with winter is melting of his snowman.
I really would like to make him happy and make the snowman survive for as long as possible.
By the way, I am a king, with a medieval-level technology. My castle is in a temperate climate - think something like middle of France - quite far from the sea.
I already have caves and catacombs where it's quite cold, but I could build a specific building if needed.
There is no magic or alchemist involved, only snow. There is magic in my universe, but a realistic solution would be better.
What can I do to make my son's snowman survive, using medieval technology?