For when your DC no longer live at home?
My parents died when I was quite young so I'm fascinated by how grown up DC interact with their parents.
If that sounds weird, bear with me 
DH hasn't lived closer than two hours drive from his divorced parents since he went to university - and often much further away. He gets on fine with them but only speaks to them every couple of months and we see them three or four times a year for a day. I just can't imagine having that kind of relationship with DD when she's an adult.
Do you live close to your parents and, if not, why? Can you envisage only seeing your DC a handful of times when they are grown up?