I was a young adult when my first grandfather died. I was told to do this or that, go here, go there and then everything would be done. So I did what I was told to do, but no one addressed how I felt about my relationship with him, or how I felt about him dying, or that I as an adult could make choices about what I wanted to do about seeing him before he died, or if I wanted to attend the funeral or how that fit into my plans/work/marriage etc. I don't think that was entirely healthy to have me fit into the woodwork of anyone else's plans for me.
So when my dad died, I called my young adult boys over and asked them to talk. We talked about all the things, how they might feel, how they wanted to handle how they felt, if they wanted to visit him before he died, if they wanted to attend the funeral. What was most important was not that they told me all this, it was that whatever decisions they were going to make, that they made choices that were best for themselves. That they each felt different and made different decisions on how they'd each handle him dying and then the funeral attendance. I told them I had confidence they'd each handle it well and appropriately for the grieving that comes with death of a relative.
There were 3 boys and myself, we each made different decisions on whether to see him before he died, then we also made different decisions on whether to attend the funeral. Then in the aftermath of sadness and all the other emotions we each came across, especially myself, we had a bonfire bbq in his honor, for me to say a short prayer over the bonfire, to share a meal and some memories we each had about my dad. It was very healing.
I think we handled it well and then when their other grandfather died just earlier this year, we had abbreviated discussions about the exact same things, and how they wanted to handle each part. Young adults need to be able to plan around work/friends/marriages to decide what is best for themselves. I'm feeling pretty confident they all had a good primer in knowing about the approaching a death of someone they loved, in knowing what things they probably should consider to get through it.
Death is usually a surprise but it is kind of a blessing to have some fore warning about it, as we did with both grandfathers.
I'm sorry about your impending loss and that of your family. Blessings.