Guests are like fish, go off after 3 days!. I sympathise with OP as I am not that keen on visitors but family you have to put up with. Hope for good weather and they go out, you don't have to go with them, you have a bad back. Also go and have a quiet lie down in your room especially when things get tough. You have your back as an excuse. It also gives your husband a chance to spend time alone with his son and grandchildren and talk about old times and maybe friends you don't know.
As for staying in the village, a couple and children, would be expensive.
I remember a post where the OP and husband were dancing around the kitchen as the visitors had gone, when the visitors walked back in as the had forgotten something.
Harry and Meghan ‘royal’ tour of Nigeria.
Static caravan purchase is it worth buying