If it was me and I had a bottomless wallet, I'd build a small garage with an overhang. It would be small enough to keep cool with a window unit and a couple chest freezers. Then I'd keep all my gear, grain, etc. in there and brew under the overhang. I'd probably run gas out there to have a dedicated burner as well.
Cooling and heating a space who's walls are up against the weather to beer storage temps would be pretty costly both initially and over time. You'd be better off with a structure that is heated and cooled to comfortable temps, then have freezers to store or ferment in
Gonna throw this out there too...freezer motors only pull a couple amps. You could slap a couple solar panels on the top of whatever you build to run em.
Like I said, that is all cost aside. Your budget will ultimately determine what you do.