If you want to see the real SF, go to city hall and count the bums on the lawn. If it's raining, go to the Central library to see them.
Don't know about Tahoe, as the closest I have gotten was driving on I-80 when I moved to CA. It's about a 3 1/2 hour drive as past Auburn, (1300 ft), the highway starts climbing. Donner Pass is at about 7500 feet. If it's going to be snowing you may have to put on chains. If they say it is required an the day you go up or come back, they will not let you go on. The Interstate gets closed if there is too much snow. They have gates that go across the highway (2-3 lanes each way) to close it.