I am located in San Franciso bay area. I have very similar to your weather.
In winter, my area 30F is average but some years going down to 28F. I see some ice on the ground and some young tips and leaves got minor burned.
In Summer, this year on June 21st was 103F but last year was 110F. Few growth tips and young leaves got minor burned for some sensitive varieties and some not damaged at all.
I am having more than 20 Cherimoya trees outside without and protection in the winter and they are at least 5 years old now. They are 10 feet apart.
My fruits cycle is from July when most varieties are setting fruits to June of the next year when I harvest my fruits.
Around November when temperature of the day drop below 60F that when all fruits stop growing. They stay almost the same size until around March or April when weather get warm again and they will continue to grow. Cherimoya have lots of big leave canopy so they protect the fruits without any damaged.
There are so many good varieties in California. For Example, Honey Hart, Orton, El Bumbo, Pierce, Booth, Chaffey, Knight, Dr. White......
You should try to grow some cherimoya inside your greenhouse and some outside to find out how well the grow.
Good luck. Happy Gardening.