:) My point was intended to be: look, it’s going to be hard work, and I suspect there is not really a way around that.

You're right that that is distinct from “hours worked”, and sure, maybe 35 is the magic number for someone.

0 hours is too few hours, and 70 is too many— so clearly there is a line there somewhere. I suspect that that line varies from person to person and even week to week, hence the point about “either be working or don’t be working”.