My family were not alcoholics just me. In my sobriety I had to cut my mother out of life. After she would visit my body would shake I would want to drink so badly. One day after her visit I realized I would/could not live up to her standards as she moves the standard depending on her mood. My siblings are still caught in mothers cycle of abuse. Sorry for stealing your thread.
Sad that siblings and I are all in our 50s.
If I was in your position, I would just jump in the car and go see my grandfather see what happens. If he seems closed off to you during the visit you can feel relieved knowing you took that step. After the visit you could always just call him once a week to say hello and check up on him.
No matter what remember your not responsible for what happened in your memories the adults those older are responsible. You have a husband now concentrate on Your house and create better memories for yourself. Don't carry the past on your shoulders.
As a alcoholic mother who is now sober. I told my girls I'm sorry for the person they could have been had they not had me for a mom...my kids are good upstanding adults and mothers whichI tell them allll the time. But they would not have the baggage and I tell them put the baggage on me not themselves. I can tell when they are starting to carry the baggage on their shoulders they sound like what you are typing. I get them to talk and they rant at me they feel better ( I feel sad for what I did what could have been different) but I rather they get the sadness out and transfer it back to me let me carry it. Luckily it's getting to be fewer and fewer times I see it in them and they rant.
You could not have changed anything your parents did or did not do you can only change what you do for the rest of your life.