Quite a long time ago, I read a scholarly book on the possibility. The author (sorry, can't remember the name) said that the likelyhood of Yeti was very low, as there simply wasn't much to eat for a creature of this size in the Himalayas.
A bunch of Rhodedendron bushes is about it.....
Also the "tracks" reported by natives were shown to be fox tracks that melt into distinctly-bipedal looking numbers as the sun shines on them.
The guy held out that Sasquatch, living in the Pacific Northwest, would have a better chance. Lots of dense woods, more food, etc.
Still, the chances are what Dr. Asimov used to call "vanishingly small".
No evidence whatever, unreliable witnesses, and a body type that conforms in no way with any existing or fossil primate.
The burden of proof rests with the claimants in this case.
Or the big furry guy himself.....