I suspect that commuting traffic will increase to eliminate this advantage. Already in major metros, long commutes suffer low speeds due to congestion during rush hour periods. Without a commensurately vast increase in infrastructure investment, I do not foresee a significant change in commute experiences from self-driving cars.
I predict that most people would not elect to live 2 hours away from offices despite being able to have access to entertainment and work while commuting.
The evidence is already here: various tech companies run shuttles to far-flung areas (Google has shuttle service from Stockton to Mountain View), yet employees aren’t moving to these lower-cost areas in large numbers.
Workers with families will have upper bounds to how long a commute they’ll endure. Their families are more important to them than being able to have entertainment, and meeting times limit the amount of time that can be used for work done while commuting. At that point, it’s approaching remote work, which is a promising idea, but isn’t a solution for long commutes by itself.
I see self-driving cars changing last-mile and replacing hub-and-spoke commutes as a replacement to taxi services and short-distance shuttles.