If you're going to do a combination car/bike tour, you could still get in the Big Sur portion of the PCH. Camp at Pfeiffer and do a couple out-and-back trips, one down to the landslide and back, another up to Carmel and back. Drive around the washout (spend half a day in Monterrey on the way), find a B&B or motel near Cambria. Next day a down and back to Morro Bay (stop for lunch!), and the next day up and back to the washout. The weather should be just about perfect in early May, and with luck, you'll beat the summer kids-out-of-school traffic.