I addressed that above.

The section from Monterey to Big Sur is only about 25 miles. It is rather slow driving in places but will still only take 45 minutes or less. The only problem there is that after you have enjoyed what is still accessible of that route, you would have to turn around and drive back to near Monterey to continue your trip. If you want to see this part, it will only take <1.5 hours - a bit longer if you atop along the way for photos, meals or souvenirs.

If you are trying to make fast time on your drive, this will be a back-track. OTOH, if you are slowly working your way down the coast and enjoying the scenery, that <2 hours or so would definitely be worth the time and effort.