Well it appears the origin of the "Bigfoot Digging In The Dirt" video has been found. The clip was originally featured in the Bigfoot documentary, Bigfoot: The Definitive Guide.
In this part of the documentary they discuss whether or not a large primate could adapt to harsh climates, since primates are known for living in more tropical regions of the world. They show some real living snow monkeys and then they show what appears to be a re-creation of a Yeti or Bigfoot.
Watch at about the 49:50 mark for the Bigfoot digging in the dirt part.