Good news! The
local news just reported that CalTrans intends to open the northern section, at Rocky Creek, this Thursday! They'll install a traffic light to allow traffic through one direction at a time, because they've only fixed one lane. But it's open. The southern slide at Alder Creek will still take a month to fix.
So first, yes, you'll need to take 101 north from San Luis Obispo; or at least, from Paso Robles. You can, if you wish, continue on 1 up to Cambria and then take CA 46 across to 101. But I'd go ahead and just take 101 from SLO.
After that, you
could cut back to the coast on Nacimiento Road. From just north of Bradley, take county road G18 (Jolon Rd) toward Jolon. At Jolon, you'll be in Fort Hunter-Liggett, and you'll need to make a couple of turns to find Nacimiento Road. You'll need a GPS or a good map. Be warned - Nacimiento Road is a beautiful drive, with killer views of the coast as you descend. But it's also a slow road. It will take you a while to get back to Highway 1. If you have plenty of time, it's a great drive.
But if you don't have that much time, then if I were you, I'd just take 101 to Salinas and CA 68 to Monterey. Then take a day trip south on Highway 1 to Big Sur and Pfeiffer State Park. The town of Big Sur is only 26 miles south of Carmel; this will be a lot quicker than the Nacimiento route. Stop for lunch at
Nepenthe's Restaurant, just south of the town of Big Sur. Killer views! You can continue as far south down the coast as you like (until Alder Creek), and then head back north to Monterey.
This plan gets you most of the scenery of the Big Sur coast, but avoids the long drive down Nacimiento Road.
In any case, have a great trip!
-Bob