Uhg. I can't read anymore! Y'all are making it way too tough on him, and he's being overly ambitious because he's a good dad and a young one at that. A compromise between the 4 hours to Tahoe and Bonanza/Star Trek reruns is in order.
Dude, don't pay for a hotel, stay at home. There is plenty to do in the bay for a 4 and 7 year old!!!!!!!!
Take it from me. I got kids 7,10,12,14,16. Save the bigger trips for later. At this age, grander destinations like Yosemite will be lost on them, particularly the 4 year old. And you will tire yourself out unnecessarily. Don't sit in traffic, ha! I live off 80 below Auburn and drive reverse flow to the bay all the time. I marvel at the mass of people leaving on Friday afternoon and returning Sundays. There is a better way! In other words, NO, you are not driving anywhere so far away! Your kids will destroy you with "are we there yet", "where are we going" (if traffic doesn't), or they'll sleep while you drive and you'll not be able to entertain them by the time you arrive. Wait 4 more years, 8 and 11, plus or minus a couple years. By 13, you'll be toast, the teen will think you're an idiot.
Okay, hometown suggestion:
http://www.pixieland.com/phone/index.htmlTrains up on Tilden?
Fairyland in Oakland?
Exploratorium?
SJ children's museum (already suggested)?
Take the ferry the angel island and hike to the top?
Alcatraz tour? Nah... 4 is too young.
Take them fishing anywhere.
Six flags Vallejo. You might not love it but they will. (Pixieland is cheaper, easier)
Take them to a you-pick-em farm in Brentwood.
Take them to the beach in Alameda and give them a shovel and bucket.
Put their bikes in the trunk, go the a high school, and let them ride around between the lines. See how many laps they can do. Olympics are coming up and they'll enjoy the track and field events better.
Pitch the tent in the backyard. Make s'mores over a homemade fire.
Think cheap. Think easy. Think 4&7, not 35. They don't care about grandiose stuff. They care about the attn you give them and that something is a new experience.
Ask people instead of where to go, what do they do in their hometown. Nobody knows about pixie land, for instance.
If you like to add structure to it, you could present them with a plan: no sleeping in the house, have to make all the food in the backyard, and each day you are gone from 10-4. Different place each day.
No TV.
New rules. Mix it up for them.
Most important thing: the house is spotless when wife gets home. Flowers on the entry table. Hire a maid, get laid.