Help! Retopologizing Trump model for animation, not sure how to go about

Greetings fellow Blendites.
I face a problem, below are two images of the model I seek to retopologize for animation.
My skill is not amazing I must say, but I am proficient in Blender and a competent individual.

I’m seeking advise on a good or ideal way to go about this. Some things to note:
*I’ve decided on mesh hair and shading it somewhat similar to how Blizzard shades characters hair in Overwatch.
*I will be animating this.
*How might the detail of the sculpt be ideally kept? Especially if I retopo the model by splitting off the hair and ears (partially due to my lack of skill in connecting the head with the ears…)

Should I retopo it as one mesh or go in parts? How may I ideally achieve either this with good and animatable topology in the face and a nice clean subdivision???

I have thought a great deal about this and made a few attempts which I wasn’t the most pleased with but they’re ok. I want to keep a lot of the detail though and also be able to stylize it some from there.

Are there any good automatic solutions for the whole thing or at least some parts?

I would greatly appreciate any help!

My humble attempt thus far. at this point I am confused as to how to best continue and hopeful of a better result. I am also curious if I’ll still be able to bake out the detail from the sculpt.

Looking good as of now, you might want to rethink the zygomatic areas.

Try to have uniformly sized polygons. You do not have to have all the faces the same size, however keep a general uniformity.