It might have taken me 7 months but I finally have an answer. I did a little messing around in out cold and I found that staying on the ridge isn't beneficial at all, this section goes off of waves of wolves there, is no infinite number but the last wave doesn't spawn until you are next to the brother. Ultimately staying at the top until you have to go to the bottom takes about 2 minutes and 50 seconds whereas just rushing to the bottom and killing the wolves once you're there takes 2 minutes and 40 seconds. I also found that the rifle is better for this section than the shotgun especially if you can grab the special ammo a long the path to the bottom so you don't have to manually change weapons.

In out cold the section where you are protecting your brother you can shoot the wolves from the ridge but you can also go down to where your brother is. I want to know if the wolves infinitely respawn until you're down near your brother, or if there are a fixed number of them. depending on which it is (fixed number or infinite number) it will change the way we approach that part of the level.