[unfocused]

I like your idea of:

"Establish a culture of taking an office break around 4-5pm then resume at 8pm for a couple hours"

as it is similar to what someone does at my work and it really helps them out.

We have one person that lives far away (45m to 1hr) and she leaves early, around 3:30pm so she can be at home waiting for the kids when the bus drops them off. Then she puts in another hour of work sometime that evening.