DSnider, you state "As you know, any attempt to turn the sailboat around from downwind toward upwind in high winds, will absolutely capsize the sailboat."
That is nonsense. If you can sail upwind, you can turn upwind. Just manage the sheets as you turn. Proper sailboats are not that easy to capsize, and the rare instances where they do capsize are more often the products of waves than wind. Except in extreme conditions, far worse than those described in the OP, there is no reason at all why turning upwind should capsize the boat. While the apparent wind will increase as you move to the new tack, the boat may be in less danger than downwind, where an accidental jibe could cause major damage. Of course different boats respond differently, and one needs to consider winds and seastate as well as searoom.