At the end of the day, how many hours/day the freezer runs is a function of how much heat flows in. Adding mass, like milk jugs of water reduces how often it cycles, but not the running hours, to a first approximation.
I added two inches of polyurethane foam to the lid of my chest freezer, and it significantly reduced the power use. Unfortunately for me, the condensing coils are wrapped around the walls of the freezer, (putting more heat into the freezer) so the walls can't have extra insulation. I would much prefer to have one with exposed coils on the back.
I have seen vacuum insulated freezers, but $$$ doesn't even begin to describe it. Even the
SunFrost freezers are $3-4,000, to use perhaps 25% of the energy of a normal appliance.
Yes, California imports a lot of power, most of it is hydro from the PNW, although the per capital energy usage is the fourth lowest in the country. There is a huge DC power line that runs from Washington to LA, with the return power flowing through the ground (saves wire). The power flows south in warm months, north during the winter. More
here, if you are interested. By 2019,
solar made up 20% of all power generated in California
Household batteries are the big thing in California at the moment; battery installations have six to nine month waits. In addition to running homes through outages, they also push solar energy out after dark, as it were, as most installations are on homes that have solar as well.
The ROI on solar in California is 5-7 years for most folks; batteries are more variable, ranging from 1yr to 20, depending on lots things.
All the best,
Peter