Trapped in his old hometown during a snowstorm, a charming con artist must spend Christmas with a dysfunctional family — and unexpectedly finds the family he never had.

Just so you know, there is a very similar Nicholas Cage movie called "Trapped in Paradise"

I don't think it will make too much of a difference, and your movie will be able to stand on its own, but you should know it's out there.

A few more...

1. Trapped in his old hometown during a snowstorm, a con artist swindles a family into spending Christmas with him, whilst cops are on his tail.

2. Not wanting to be alone over the holidays, a con artist seduces a sweet wholesome woman, but must first spend time with her family, whom he grows attached to.

I can't figure out whether his main goal/macro intention is to get out of there (and thus get to a locker filled with money) or to not be alone over Christmas.

The Inciting Incident - he's on his way to locker of money. His car breaks down. Mechanics say two days. Snow storm happens as well. (The cops on his tail was going to happen later.)

Anyways - not wanting to be alone in a motel room, he seduces our heroine (the sweet wholesome woman).

And in order to spend time with her, he must spend time with her weird dysfunctional family, whom he grows to love.

He then spends a good chunk of time pretending to be something he's not.

And then the cops are on his tail...

I think he needs an objective goal related to his "trade" and character.? Like doing what he does best: the family that befriends him is the mark for his latest con. But then a snowstorm traps him at the scene of his latest crime.? Consequently, there's more dramatic tension.