We feed MIL and she pretty much eats what we eat (as long as I portion hers out before I add the pepper!). I like to cook some "staples" of our diet in quantity and freeze so that I don't have to make a meatloaf (for ex.)every time we want one.
In my freezer I keep meatloaf,spagetti sauce, chili meat, steak in gravy, beef stew (MIL fav), pock chops/green beans in mushroom soup, ham/bean soup, turkey meat/broth for pot pie or soups and (NOT for MIL) shredded chicken/sauce, shredded beef/sauce and chili verde. And usually 2-3 kinds of soups.
I try to do a crockpot of something as soon as I finish the last one from the freezer. Sometimes I have a kitchen day and make up 2-3 big batches of food for the freezer.
I guess I just have trouble with your comment about HAVING to cook every 3 weeks as I cook nearly every day (and like to). But the way that I cook means a majority of dinners don't require much time as it starts with something from my freezer. Likng to cook doesn't mean that I WANT to spend a lot of time on it all the time :-)