My thanks to totient for pointing at ThermoCube, which looks promising for connecting an oil heater inside the RV for times we want to store it semi-hot without burning through a lot of propane or running the heater unnecessarily. As long as we can keep the temperature above freezing, that would likely be enough.
Meanwhile, I am slightly amused to see people bundled up like arctic explorers against the Bay Area cold spell of weather around 8-10°C. They looked at me funny as I strolled along in shirtsleeves without even a jacket. It's twenty degrees warmer here than at home, and feels almost tropical by comparison.
Without a steering stabilizer, I generally kept the speed down to only 55 mph except when the heavy traffic coming down the mountains forced me slower. That, combined with the trip being mostly downhill, led to a 20% improvement in fuel consumption, albeit that's an improvement from 9.5 to 11.5 miles per gallon. The Stone Ford 460 engine is never going to be what you'd call economical. Also, with all of my usual stops, it took me nine hours to make the trip. I'm glad I don't have to be up early tomorrow.