The flyer in the bait shop states that Zeke was 36 when he went missing in 2017, but Zeke says he was 15 when his sister was killed in 2006, so he should be 26 in 2017.
There is barely any snow on the ground when Michaela and Zeke return to the cave he had been trapped in. The only way that could happen was if Zeke traveled through time after he escaped from the cave, but it was the time travel "turbulence" (for lack of a better description) that caused the ice blocking the cave to break open enough for Zeke to escape. The cave that they went to, he would easily have been able to walk out of; the quantity of snow that would block the cave entrance would not have melted away so quickly.