You have an excellent itinerary. Avoiding weekends in tourist areas is a good idea. Best place to stay in Yosemite is in the valley at either the Yosemite Lodge or the Ahwahnee Hotel. If you can get reservations at this late date. Must sees in Yosemite are: Glacier Point, tunnel view, and touring the valley half of which is closed to cars so rent bikes to see all of it. Do not take the guided tour shuttles as the tour guides loud amplified constant talking spoils the serenity and beauty of what you are seeing.

Not sure where at Lake Tahoe you are staying, but you could take the "loop" trip. Take I-80 out of SF until Sacramento. Take Hwy 50 to South Lake Tahoe. If you enjoy wine tasting, there are some wonderful local wineries in the Placerville/Camino area (free tasting at many of them). Local growers call it the Apple Hill area. Continue to South Lake Tahoe. Spend the night then continue around the west side of the lake up to Truckee. You can then take I-80 back to San Francisco.

Good plan. US 50 out of Sacramento is the most scenic.
IMO a little more scenic return route would take you on I-80 to SR 20 to Nevada City, Grass Valley, part of the gold rush country and then SR 49 back to I-80 at Auburn.

Thanks for all the feedback. Much appreciated.

Regards

Good luck on finding anything in the park. This is the official reservations service.
http://www.yosemitepark.com/lodging.aspx

The problem is that they take reservations up to a year in advance. I would plan your trip around the hardest thing to find, which is a reservation for Yosemite.

It might be best to drive to or from Yosemite from South Shore. It's the back way, over the Tioga pass, which is beautiful the time of year you're going.

Boom boom, I almost suggested the detour via Nevada City. Love the area. A visit to Empire Mine State Historic Park near Grass Valley is very interesting.

Personally I would find it very discouraging to drive all the way back to SF for the weekend. That's a lot of extra driving. I'd go to Tahoe and then take Highway 395 south to the Tioga Pass entrance to Yosemite. You could spend a night in Bridgeport or Lee Vining on the way to Yosemite. A side trip (for a few hours) into Bodie, the largest and best-preserved ghost town, would be worthwhile, too, and Mono Lake is very interesting.

I wouldn't go back to SF either. From Tahoe, try going through the gold country on Rt. 49 and finding a place either in Placerville or south of there.

I wouldn't either, it's about 4 hours each way to both Tahoe and Yosemite, and probably the same from south lake Tahoe to curry village in Yosemite. So you save 4 hours driving by not returning to SF in between. That said, your reasoning is sound!

I second, third and fourth the last 3 comments--too much driving, too little time to see all 3 wonderful places. The best part about driving from Lake Tahoe south on 395 to Lee Vining and on into Yosemite Park is that you get a TotallyDifferent view of California. The granite fields and views from the top of the park are stunning. Do it early in the morning for great pictures.
You may have to stay outside the park at this late date...make reservations now!
The ghost town Bodie is wonderful, well worth the drive on washboard dirt roads. your child won't forget it. "Goodbye God, I'm going to Bodie!" the little girl said. Mono Lake is another strange anomaly. A short detour there is quite interesting.

At this time of year there's no dodging crowds, so get up really early and beat the sleep-inners at Yosemite. Early morning is magical. Then get out of the Yosemite Valley during the day unless you are on a Ranger hike. Drive back down after the hordes go in for cocktails, and enjoy dusk in the valley; there will be plenty of light til 9 pm. Have fun