Campfires or barrel fires too keep you warm without burning your fort/campsite down,
Fishing and spear fishing in the lakes when they are implemented and rivers for food.
a higher amount of wildlife to hunt (Moose, Caribou, Grouse, wild turkeys, Raccoon’s, coyotes etc.) for food.
also crocodiles and alligators to inhabit the swamps.
sorry for the lack of detail im a little pressed for time i may explain further a little later.
The fire stuff will come into play soon enough, we have a dude working to make temperature have more of an effect on the player.
Fishing is a good idea, I had it in before and will re-implement it at some point.
I’m not certain about the wildlife, we’re in rural New England here.
Mutated crocs and gators is good though.
Oh god, more shit spawning around swamps.
There’s enough wolves trying to eat you every morning if you camp in the woods that it rots before you ca eat it all. So although more variety of animals would be good, more animals would not.
personally i agree that adding more animals would probably be more of a pain for players rate of survivaly but i would prefer it no other way, the harder the better, also it is kind of hard to believe surviving off of rabbits and squirrels alone, even the occasional deer, however constantly trying to kill packs of wolves everytime you get attacked by them can be pretty difficult when starting out. and a wider variety of non hostile animals will add a better economic system then relying on scraps within the cities, also means more trade, and can also provide reasons as to why the said wolves are not weak from starvation having to rely on people as food, or trying to catch the squirrels or rabbits.
and another reason to add more animals, or hostiles will be to vary them up, i get pretty bored when i know how to evade and kill every creature because there as so little.
Currently, there are no known breeding packs of wolves in New England 
While they make great enemies, as far as realism goes - the idea of them attacking humans, and the numbers in which they appear, is completely wrong.
They make nice meals though, just get a bow and some arrows!
I think the wolves being in makes sense. The wolves are used to dealing with zombies, which are universally hostile. Also, wolves would spread out again once society falls.