Which wineries in Sonoma Valley have outdoor seating?
Spill lists 29 wineries in Sonoma Valley that confirm outdoor seating. Walk-ins are welcome at 5 of them, and 21 ask for a reservation. A typical tasting is $40. The wineries themselves maintain the facts on 2 of these pages.
Is outdoor seating at Sonoma Valley wineries first come, first served?
It depends on the winery. Many seat outdoors by reservation like any other tasting, and a few keep the patio for walk-ins. The winery's page says which, and weather can close a patio on the day.