I know. Quoting Whitman, "I am large. I contain multitudes."
> Your options are to either build up or to build out.
Or, in a word, arcologies.
> Arcology, a portmanteau of "architecture" and "ecology", is a field of creating architectural design principles for very densely populated, ecologically low-impact human habitats.
> The term was coined in 1969 by architect Paolo Soleri, who believed that a completed arcology would provide space for a variety of residential, commercial, and agricultural facilities while minimizing individual human environmental impact. These structures have been largely hypothetical, as no arcology, even one envisioned by Soleri himself, has yet been built.
https://en.wikipedia.org/wiki/Arcology
If I had my druthers, I would roll up the low density stuff into arcologies and rehabilitate the old creeks that ran and still run to the bay. Use Permaculture (applied ecology) and passive design. IIRC the Australians were going to build a huge multi-acre combined solar chimney and greenhouse to generate electricity and grow food. &c.
https://en.wikipedia.org/wiki/Solar_chimney
We have all the solutions we need (often they are decades old) we just have to clue up and get crackin'.
"I don't think it would be the best of all possible worlds to make the bay area look like Manhattan or Tokyo."
These two sentiments are in direct conflict though. Your options are to either build up or to build out. Building up will preserve the nearby wilderness; building out will see it turned into low density housing, roads, and terrible traffic congestion.