Capsizing is not an option.
No, seriously. It sounds like a bit of a tongue-in-cheek answer, but there's really no excuse for getting yourself caught in a situation where you're so over-canvassed that a capsize is a reasonable possibility--especially with a rig as easy and quick to heave-to and reef as a lug yawl. Not if you're voyaging solo. The water temperatures around here will kill an unprotected swimmer from hypothermia pretty quick, even in the middle of summer. Every year or so there's yet another novice kayaker or a flat-water canoeist who gets in over his skill level without knowing any better and dies out in the straits. If I were to put myself in the position where I capsized halfway across the Straits of Georgia, I wouldn't expect more than a 50/50 chance of survival, even if I did get the boat straightened out quickly, because of cold-shock. Even people wearing survival suits sometimes die from the sudden involuntary gasp that can happen when your head is immersed in 40º water. It only takes a few minutes. The only acceptable strategy is to not go in this water.
That being said, yes I do have bouyancy chambers, and yes I do have protective clothing, including an actual drysuit that I will wear when the weather seems especially threatening, but I don't place any faith in any of that stuff the way I put my trust in planning ahead and sailing as conservatively as the situations warrant. As a former student of human psychology, I am all too aware of the cognitive bias of Risk Compensation where people who have trust in mechanical safety devices end up putting themselves in even greater danger because they think they are protected. Especially "experts" and former experts who don't realize how slow and fat and old they've gotten over the years, or how much they've gotten used to rationalizing and minimizing the risks due to familiarity breeding contempt. Even though I have the built-in bilge pump and the sealed compartments and the gear, and I maintain and update my pump diaphragm and hatch-gaskets religiously, I do not have any illusions about getting back aboard easily if I should go swimming by mistake and be cold and wet and terrified ten miles from the nearest land. I try to make sure I am comfortably nervous and scared every time I start to do a crossing, and I believe this keeps me safer.
You should not even consider doing solo voyaging until you've practiced your skills and strategies to the point where you've reduced the risk to what you find acceptable. And bloating up the weight of my boat to make her totally self-bailing or what-have-you would substantially decrease the enjoyment I get from rowing her and compromise her mission. Rowan is already at the upper limit of size for a single guy to row her for long distances, and because I have made the conscious and emphatic choice to insist upon zero-emissions boating in her, I must work within the compromises this choice mandates.
So yes, I do think I am likely enough to be able to recover from an accidental capsize to continue to not want to make any changes in my boat right now. But I don't think that capsize-recovery is one twentieth as important for single-handed cruising sailing around here as capsize-prevention. I really, really don't even consider it as an option, and I sail accordingly. There must be no schedule or time-table out on the water other than what the tides and winds permit.
Sea Kayaker Magazine did a very informative article on hypothermia and cold-shock that you can read here.