Don't do it just because your parents need support, that's insane. If you want to move for other reasons, and the whole family want to move, then absolutely do it. But imagine if someone in your family was desperately unhappy having moved and resented it. You'd probably be spending more time with your side of the family too, and could end up in much more of a caring role than you'd anticipated and your own family may hardly see you for a number of years. What if it's the other way and your elderly parents die within a year or two of you moving everyone up there - would you then be happy to stay there? What if each member of your immediate family disagree as to what to do in those circumstances? What if you all realise it was the wrong decision but financially it's too hard to move back.
I've had experience with relatives who beome elderly and they don't live close by and have no children of their own (not parents, but as the closest relative you do feel a sense of responsibility). One 3-4 hours away and one the other side of the world. Yes, it becomes v difficult when they age to support them from afar, there is little practical help you can give, and the guilt is terrible when it's neighbours who end up being put upon. But when you have that conversation about theiir plans for later in life and they decide they want to stay put then what can you do?
I know a couple of people who retired and decided to downsize. Then they thought that as all their family ties had moved away from themfor work etc then what was stopping THEM moving to their younger family, who have all their lives ahead of them? So they did, and were positive about making a new life for themselves. I think that decision needs to be made at an early stage, though, when you're a relatively fit and well retiree, as if you leave it too long the move can feel like too much of an upheaval.
I don't konw how I'll feel when I get to that age but at 50, as much as I love my home, I'm aware that I could end up a lonely old woman unless I am open-minded to the thought of moving towards wherever my family may be.