Some of the replies on here are hilarious- of course the OP's post is about her feelings, it's written by her! There's some people on here who do nothing but snark...
Unfortunately OP there are some older people, and in 80's is older in terms of likelihood of illness/bereavement, that find it very hard to face up to what's likely to happen. I've seen it happen a lot around me- active fit older people sprightly up to 80 odd but then they do often hit a wall of decline, even in small ways (e.g like skin doesn't heal so well, arthritis prevents walking as much) as well as the big illnesses. It is annoying that they are not planning for and taking account of this and just are burying their head in the sand.
I think you have to encourage your husband to be matter of fact about it- decide what is a reasonable amount of time to spend there per month and that will be that. It is easy to say this, and what will probably happen is you do end up living on the motorway or trying to arrange carers from afar or not being able to help with day to day activities and that is stressful and frustrating for all concerned- and will negatively affect them.
Some of the choices my elderly relatives have made in the past few years have worked very well (mainly being very close to relatives!), others, who refused to move from their large houses and thought everyone would come to them are still cared for, but it has been incredibly stressful all round to the point some of the caring children have almost had a breakdown- as they are still working and trying to live their lives whilst caring for really quite elderly parents.
To deliberately move out of the way of help in mid-80's is willfully blind to the coming future, it really is, especially as already they are expecting you to rock up and start caring, just farther away and in a way that will make it harder to live your lives.