The problem is that once boats hit say 40 feet and above, the loads get to the point where one really needs to be careful, especially in storm conditions- and this includes setting drouges and parachute anchors. So even though one may appear to be safer on a 40 foot and above size boat, in reality 35 feet may be a better number for maximum size.
Of course all of this is much dependent on the skipper training, ability, and physical condition, as well as the crews if one is not single handing. The other thing to remember, say it is you and you spouse double handing a 44 footer. One gets injured, can the other single hand the boat in a storm?
I don't agree with you that a 35ft to be safer than a 60ft boat assuming the boat is prepared to be solo sailed.
No, not a 44fter, I sail a 41ft boat. I can sail the boat alone even on a storm even if I will do everything not to sail the boat in a storm in first place.
On a storm my boat will have considerably more stability and RM than a similar typed 35ft boat.
Regarding my wife no, she would not be able to sail that boat in a storm or in perfect sailing conditions. She would not be able to sail a 35ft either.
She don't likes sailing and refuses to learn. She has the right to do so and I am happy that she likes to voyage and sail on the boat with me taking car of the sails.
You are mistaken in thinking that a smaller boat is always easier to sail then a bigger boat. It depends how the boat is rigged and on the weight of the boat. My boat is less heavy than most old 35fters and in a storm the amount of sail it needs to sail and make good speed is really minimum.
Even with as little as 15/16K of wind the amount of sail to go at 8K is small, with both main and genoa reefed. Off course I could go at double figure speeds downwind with full sail but then the boat would not be easy to sail one by a solo sailor, as it is with the reefed sails.