Thank you all for your helpful suggestions.
I suspect that the moon and open clusters are the way to go. Per your advice I have also identified reasonably close sites with darker skies, in particular Topanga State Park. When my kids were small I used to take them to Mount Pinos on nights with a new moon, or nearly so, so in spite of being light polluted city dwellers, they got a sense of what the real sky looks like. I look forward to giving the same gift to my grandkids.
Yes, the Topanga State Park will be darker than downtown LA, but not very dark, alas. On a clear, dry, moonless night, perhaps a mag. 5 limit at the zenith.
Go a little further to the intersection of Mulholland and Point Dume roads (above Thousand Oaks) and the skies become about suburban dark (30 minute drive from west LA)
[I used to go to Boney Peak in the Santa Monica mountains many years ago (fantastic view to the south!!), but the LP has gotten too bad to justify the 1 hour drive.]
Extend the drive a bit further north on the 5 to Pyramid lake (Templin Highway) and it's even darker (45 minute drive), maybe mag.6 at the zenith.
A little further to The Chuchupate Ranger Station parking lot at 5000' (west of Frazier Park) and the sky is much much darker (60 minute drive), perhaps mag. 6.5-6.7 at the zenith.
And that parking lot won't require chains, always the possibility for the Mt. Pinos parking lot at 8350' (90 minute drive), perhaps mag.6.8-7.0 at the zenith.