I think they already have the house. Now they want to know if they can use it. I live in Florida and we are loaded with people from, Canada, the UK and Germany who come over for the winter. You can get Marmite and decent (not sugary) orange marmelade in the supermarkets where I live. We even have a German bakery. You are far from the first.

So, if you can normally get a six month visa, you can do that once a year forever, as far as I know. There are some countries with visa waiver programs, and some that get long term visas that allow six months per year in the country. I think India is one, mainly because India gave me one like that, good for ten years.

Check it out, of course, but just from the sheer numbers where I live, you probably will be able to work it out.