Is it guilt you're afraid of? Or grief? Cuz it's a hard, hard line to cross when you give up your parent for lost (go no-contact)
I moved across the country from my AF. I still talk on the phone to the rest of my family, including my codie mom. But I got to the point where I can't hear my dad's voice without getting upset over how little of a parent he was (at many times). I used to feel guilty because I thought I was letting him down. Now I feel sad because I realize that he and I are both letting me down by pretending to have some kind of pain/guilt-free father/daughter relationship. It's a charade for him to feel successful, and if/when I get too comfortable, it's a dumping ground for his dysfunctional feelings. With the help of therapy, I bypassed the guilt when I made the big move. I was unprepared for how much grief I felt... for wasting time there, for the relationship wasted, and for finally showing even to myself that this person treated me badly enough to be cut out from my life.
Since moving a few years ago, I've come much closer to terms with: he'll never be the dad I wish he could be, he is too immature to be a mature adult around me (much less a parent), and I will continue to actively hurt inside when his childish disregard for my feelings comes out in his behavior. For two years I didn't talk to him at all. Last year I felt stronger in my convictions, and made a brief one-day trip home on my volition (not his). I'm content to know the door is open when I choose. I'm absolutely NOT at the mercy of his moods or drama anymore.
If you suspect no contact will better manage your emotional health, why not try it? You might emotionally detach more wholly, and feel better about how to deal with your dad in a few years (rather than remain in this stagnating relationship dead zone you're in already). You're the adult running your show now, so you might as well live your life. Because while you're thinking about things left said/unsaid in case he dies tomorrow... the reality is, he's not spending his time concerned about the same for you.