...still get 3 or 4 visits a year mostly when we are not dressed...
I'd remain undressed (just kidding).
We don't want to move because we really enjoy where we live and both have careers that keep us in the area.
I've asked politely that they stop calling but like the "Godfather" they keep "pulling me in."
I think it's ridiculous that you should even consider the possibility of moving because of them. They have no authority over you or any member of your family.
JWs love having the last word on everything. They hate the fact that you are free to do whatever you feel like doing and they have no saying on it. They might be provoking a situation where they can have the last word, simply because they just want to be right all the time and in everything.
Are the visitors the same people? If they are, I believe that you can be more direct (no need to be nasty, though), especially since by now you should have minimal or no investment at all in that organization.
I was very nasty and inappropriate in the way I send the message that I have no interest in any contact with them (I was too immature and too angry at the time for me to know better). However, I do believe that there wasn't going to be any nice way of setting boundaries with them.
Sometimes it takes a more direct approach to have them understand that they are not welcome when they come in to make you go back to their congregation.
If the people who come in to visit are not the same people, then my guess is that some idiot elder is giving a directive to have people visit you. In that case, I'd try to address the source of that directive, who's sending them. Then I'd be direct with that person.