PH is a huge issue in California and it's been the most effective thing I've changed in all my plants. The heavy calcium is also an issue in most water systems, especially so in wells like I'm on.
It is a big challenge to pull off what you're talking about - but I respect the hustle. My greenhouse in 9b has been pretty effective, but alone it's not enough to push much past one zone. If you have a heavily insulated greenhouse, that's going to be helpful all around. My gh has no insulation properties and is only good for about 10f of protection - which is plenty for what I'm pushing. I only needed a heater on one 26f night and it kept the GH at 37f all night.
As others have noted, you need layers of fall back plans - I bought a 6kw diesel generator for my house, well, grow lights, and fans. It has almost 200 hours of use since the power goes out so often up here on the mountain pass. I deeply recommend it having seen what happened in Texas.
It will be very costly in $ to heat, water to spray, and stress to manage. Personally, I've backed off on really pushing past my zone because of how involved it is - but if you have the time, money, patience and space I applaud you. I just buy mangosteens, mangoes, and ultra tropicals at the store when they're in season and that suffices for me.
Keep the forum updated though, it will be really cool when it's all dialed in. Check out Mark from Texas greenhouse set-ups, he probably has the most well built and sorted stuff I've seen with misters, fans, heaters, and so on.