The sail from Long beach shouldn't be too much different than from MDR once they round the Palos Verdes point. You should still be on a reach, maybe a close reach but not dead into the wind for sure. Obviously it depends, but that time a year it's pretty consistent.
Also, just FYI, Laguna doesn't have a harbor. IF that is what you would need, try Newport or Dana Point. Newport has a nice fireworks show on the Forth, I'm sure DP does too.
Most likely you won't get a mooring at Avalon around the Forth, you might have more luck at the Isthmus.
BTW, Magnetic course to the ISTHMUS from Los Angeles Light is 204 deg.