In a comic Batman would win 90% of the time, he's just that good. In a forum i would still give him about a 75% chance of taking this due to character and his ability to dodge most if not all of Wendigo's hits until he gases the freak to sleep. This would also depend highly on the Wendigo that he fought. I don't see Batman dying here, because if he saw this as an impossible situation, he would BFR himself and devise a way to return later with something that could put Wendigo down.
Well the Classic Sasquatch has the durability to withstand hits from the Hulk with no damage which means Batman attacks will do absolutely nothing to Wendigo he also has a superhuman healing factor which means gas shouldn't work and on top of that he has superhuman speed beyond the finest athlete which means he is faster then Batman. Wendigo destroys him.