I feel like the Wolves being dangerous, moreso than real life, feels like a good fit for the setting. If things are desperate for the players then its probably desperate for the worlds natural predators too. From a game design standpoint however i feel they could be better telegraphed. More than once early on i've been backing up poking a Drifter to death only to suddenly die, think "that can't be right he wasn't even touching me" only to see a chat message i was killed by a wolf out of nowhere.
Theres the howling in the distance but honestly it seems to lack any real depth to it to tell if its near or close and may as well just be ambient sound effects unrelated to mob spawns. For all i know it very well could be.
Some sound effect for sticks breaking or a low growl telling the player to stop, turn around and move away or move ahead and expect a fight would help a lot especially in areas with lots of brush where visibility can get pretty short range.