is there an actual, provable link between Odin and Santa Claus, or is this a modern day invention? Because I've heard this claim being spread throughout the internet but I have to find any real proof for it. Also I read the claim that originally, it was Odin who would come in the night during Yule and leave treats for children but I've yet to find any source for this claim.
No.
/u/KiwiHellenist has an excellent post about how Pagan Yule was largely a 19th Century invention here.