I'm not the GP, but I think its' not a very full-time role because movement is slow and progressive. They have the next 18 months of what the company is going to do locked down and defined. I would also suspect they have strong 2nd level exec leadership to handle day to day. Elon only needs to get involved on big strategic decisions and crises, plus routine periodic budget and financial assessments.

I'm sure he's still working more than 40 hours a week across all of his companies, but I don't think he needs to be in the room for every major meeting.