Paul_R LMAO! I live about 20 miles south of Eureka, along the coast also. A little nicer weather here, by maybe 5 degrees or so on the average, but we do start whining when it gets north of 75 degrees! If you go even 15 miles inland, it is another story, like you said, 100 degree days are not at all uncommon.
Arrow 5 has been hunting their grounds hard, too hard for years. They used to produce giant bucks consistently, but those days seem to be past. I'm sure you could turn up a decent representation of the species, but not much more.
I've hunted most of the wilderness areas in NorCal that have blacktail. Cam Hanes wrote a book on bowhunting blacktails, I wrote the CA section for him. I think you can still pick it up off of his website. There is a lot of info in there. I'd focus on the Trinity Alps or Yolla Bolly if you are interested in a DIY backpack hunt.