Yikes!
Y'all can set sail without me in those conditions. I'm staying in my nice, cozy, safe anchorage. I'll wait for a better weather window.
I thought this hypothetical adventure was supposed to be a pleasure cruise, not a forced voyage to be completed under duress.
The question is about sea room along a lee coast. So, one could pick any force. rgranger said “riding out a gale hove-to.” Beaufort Force 8 is a gale; so, that’s where I got it. Hardly anybody would leave a cozy anchorage to go into a gale just to heave-to and get battered. Unless maybe you’re signing on to one of Kretschmer’s heavy-weather sailing charters.

Pick Force 5, Fresh Breeze. Same question. What’s the minimum sea room for 6 hr of heaving-to? Maybe you’re seasick and need to get some rest, and your crew doesn’t want to stand watch alone, etc. It’s an academic exercise to test the skipper‘s understanding of what’s going on--situational awareness—and how to predict drift/set, hove-to. The safety margin. Or, you could make it 4 hr, whatever. You don’t want a 50-question questionnaire. Every single question has to test the synthesis of a few mini ones.
That said, Force 7 and 8 near gales and gales, respectively, are not uncommon along the CA coast. You could encounter one traveling between SF and San Diego in summer. Last summer when I was at Morro Bay a crew in a Catalina 36 traveling down from Half Moon Bay stopped there. Had reached much of the night under gale conditions off Monterey and Pt Sur where it gets real nasty they tell me. So, a “fun“ trip for a band of hearties from the Bay Area to say the Channel Islands, you might elect to be with folks who can safely sail into Cuyler Harbor on a 40-kt broad reach, b/c that’s what you may well get. Yes. Could or should stay in Morro Bay or Port San Luis until better weather appears, you might be there a couple of weeks waiting. But, what spots!!