Texturing/Material Question

Hello, I’m currently looking at a set of textures for a character that uses multiple materials. Each material uses its own texture set, and each texture set has 6-7 textures each (PBR Metalness workflow + Cavity Maps) this amounts to about 75 2048x2048 textures.

I’ve started to go through the process of creating a few texture atlases to optimize the number of textures used. This will later reduce draw calls when imported into a game engine (my intention, as this character was designed to be used within a game engine).

My question is this: Is more efficent to use a 4096x4096 Texture atlas and have 4 materials/texture sets or should I go with a 8192x8192 texture atlas and have only one material? How I think about this is that the advantage of using a texture atlas to reduce draw calls becomes a moot point if the texture is too big.

Any insight to this would be appreciated, my targeted game engines are Unreal Engine, and Cryengine. Thanks for the help!

You probably should be reading these instead of asking here because the requirements come from the targeted software instead of Blender, and these information sources are more official than BA.org.

UDK | TextureOptimizationTechniques
Texture Streaming | Unreal Engine
Balancing Visuals with Performance | Unreal Engine
Performance Guidelines for Artists and Designers | Unreal Engine
Quick Tip: Optimizing Textures In Unreal Development Kit

Performance - CRYENGINE Manual - Documentation