While i love the concept of zombies speed/stats being subject to external effects, far as i recall all suggestions in this regard have been avoided thus far. weather due to the level of complexity/aspects/features you’d need to introduce in order to justify an overhaul of something that ‘just works’, or due to avoiding re-balancing the entire system around niche mechanics.
what i dislike about this approach is the separation of effects on mobs from the effects on the player / npc’s
if anything the effects should be similar unless it is something very, specific. to contradict what @ppalda0421 points out, Low temperatures tend to make things more brittle aka decrease elasticity(dampening)
however the mechanic you describe could probably be condensed to a single temperature based buff i’d imagine, so who knows 