I am in a similar situation. I don’t have elderly parents, but would like to move nearer to family and DH would like to stay where we are and downsize. From my point of view, moving is obviously the right thing to do, but DH sees it differently, as we do have a lovely quality of life here. I don’t feel I have any right to try to force the issue, as we are both equally entitled to have our opinions taken into account, so we are still discussing it. Ultimately, we will have to come to decision, but I think if I was adamant that we need to move, it would be counter productive and you do need to respect your DH’s point of view in this. It is understandable that he doesn’t want to relocate his life to an area that neither of you has chosen and which possibly doesn’t appeal to him. You obviously love your parents very much and are prepared to uproot yourself to be close enough to care for them, but, even if your husband is fond of his in-laws, I don’t think he can be expected to change his whole life for them.
I agree with previous posters that your choices are either to make sure your DPs have support in place and visit them frequently or for them to move closer to you, otherwise you are effectively prioritising your parent’s needs over your husband. Your parents love you too and surely wouldn’t want you to jeopardise your marriage because of them.