I have not had a problem with my indoor-only cats. They never went to the door when someone came over.
Depending on which cat it was, some just didn't associate the door with anything that mattered to them, but more of them just didn't run straight to non-family members.
It sounds like you're definitely going to have extra traffic this year! Is this the same person who puts up the amazing Christmas displays?
Love All Life, Thank You For Posting! :)