Yeah, I would definitely keep the car. Just don't drink too much at dinner, and you'll be set. Before you go to the valet, look around for street parking. As a SF native, I almost never valet my car at a restaurant. It is a surprisingly parkable city, especially around Gary Danko. Just cirlce around a few times, and you will see plenty of street parking.

I never valet at Gary Danko because they put it on your bill at the end so you end up paying tax and tip on the valet, then you walk outside and tip the guy again!

Parking after 6pm is completely free in San Francisco (except by the waterfront near the ferry building), so you can park at any of the metered spots in SF. The 2-hour zones also are not in effect at night. Just check the meter itself and the signs once you've parked your car. So if you're a cheapskate like me (but like good food), then try to park on the street. It's worth the effort to look. Which day of the week are you going?