I never saw the episode of TV's The Westerners that Will Penny is based on, but I've seen a good many episodes of that series. Brian Keith starred, and I can imagine him in the title role in this movie. In fact, it's easier to imagine him in it than Charlton Heston, who was more apt to be playing Ben Hur or El Cid or Moses by this time in his career.
The story's a small one. Will Penny is an aging cowboy who's hired to ride a fence line on a big ranch during the winter. He's supposed to stay in a small cabin, but when he gets there, he finds it occupied by a woman named Catherine (Joan Hackett) and her son. They'd hired a guide to take them west, but he's left them on their own. Their only chance to survive the winter is to stay in the cabin. Penny gives them a week. Either they move in that time, or he puts them out.
At some point during the week, Penny runs into the Quints, a family out for revenge against him. He gets shot up. Badly wounded, he manages to get back to the cabin, where he's forced to spend a lot of time recuperating. Before long, there's a whole lot of bonding going on.
Check out the cast for this one: Slim Pickens, William Schallert, G. D. Spradlin, Donald Pleasence, Ben Johnson, Bruce Dern, Lee Majors, Anthony Zerbe. Can Penny settle down and have a family? Will the Quints return to complete their revenge? Rent the movie and see.