So, my mother-in-law passed away late last year from a crazy disease that spontaneously struck her, and there was nothing that could be done about it. From Thanksgiving to Christmas she went from somewhat able to passing. In some ways I think that it was a relief that she was taken from us so quickly and that the disease isn't painful, but still.
The hardest thing has been supporting a partner who has been trying to prepare for this, due to her age somewhat, but just in general. In their case this was not sufficient in any way, shape or form to deal with what went from treatable diagnosis to a death sentence in days.
It took a massive amount of work and coordination to get things together for a celebration of life, then putting her to rest. The family has means, and no expense was spared in paying tribute to this person and enjoying the company of her family, friends, former colleagues, and all.
If you've done this already, I feel and see you. If you haven't, please don't just ignore the eventuality when you'll have to face it in some way. Only certain circumstances would leave you ignorant of such things, and that's a position with severe trade-offs.
Support your family, friend, and whomever when this happens. Don't add to the misery or grief, but do what you can to make it _better_ for everyone _despite_ the circumstances.
It's better to get it done and return to whatever state-of-affairs you were in than bicker and fight over the grave.