I saw a TV programme that suggested that the legend of Father Christmas coming down the chimney originated in Lapland or Siberia or somewhere. Somewhere that has a solid few months of snow anyway.
These people lived in Yurts and they would have a fire in the middle with the smoke going up and exiting through a centraL hole in the roof. As the winter set in the snow level would rise to at least the roofline of the yurt, sometimes higher. The hot smoke from the fire would keep the chimney hole open and it became the only way in or out of the dwelling.
In the middle of the winter a "medicine man" would travel around bearing preserved foods and herbs etc. He would arrive on a sleigh pulled by reindeer, come down the "chimney" and distribute goodies to everyone.
Sounds feasible to me.
Our modern red and white Father Christmas was invented by Coca Cola in the early 1900s usurping the guy from European legend who normally wore green and brown.
If you think about it he is a Coca Cola logo personified.