Eddiebuckle

I remember reading a definition of stress that is pretty accurate: "Stress is what occurs when the mind overrides the body's impulse to strangle someone who desperately needs it."

Stress is what happens when we try to impose our will on a situation, knowing that it likely will fail.

I would venture that a significant portion of your stress is not specifically about your vacation, but rather that your vacation is pushing the flaws in your relationship front and center. Your vacation will not play out how you want work because your ABF cannot be the person you want him to be. He is an active alcoholic, and until that changes there is no possibility of him being what you need, your vacations being what you need, or your life together being what you need.

If a vacation alone is far more attractive than one with him, what does that say about the rest of your life so long as he continues to drink?

I would suggest you go alone, and don't apologize for it. He has every right to choose to drink, and you have every right to go or stay and watch this train wreck continue.