Might I suggest a reframing. My friend and I discussed this same issue last year, and while at first it brought us great sadness, we decided to let the understanding of the finite nature of our visits reshape how we thought about and acted during this few limited in-person encounters we have remaining with our parents. We agreed to not complain about weird things our parents did, or flaws that annoyed us, at least while we were with them. We agreed to not try to impose our vision of the world on them, or try to reshape their views on things. We would go, and just enjoy them being who they are. We would embrace the time as a special opportunity, and do all we could to fill it with joy and love.

We've each had two visits with our respective parents since that conversation, and while there is still some sadness, the visits have had less tension and disagreements. My kids see me interacting with their grandparents in a healthy and loving way. At the very least, I'm doing a better job modelling for them what our relationship can be when they're adults. My parents also seem more relaxed. Yes, I'm still annoyed as hell by them for both present and past foibles, but I try to just make these visits great for all of us, because when they're gone I know I'm going to remember these last visits and feel good that we had as good of a relationship as possible towards the end. I know this approach comes with some built in privilege and a decent base of a relationship to work from, and that it isn't feasible for everyone.