During a notoriously bleak winter, a wanted frontiersman must protect the family he?s taken refuge with from an unscrupulous company that wants their land.

Good. A few tweaks can elevate it…

Bleak is not such a bad thing and it doesn’t get worse with notoriously. Or is it clearer to say a harsh winter?

Wanted for murder? Robbery? Offer a sense of the tension between the family and him.

Unscrupulous is redundant and better to add specifics. For example, “A land grabber’s ruthless henchmen.”

Still, it sounds straightforward or common. Not a terrible thing if the writing is great. But try working on the theme now (sometimes it becomes clearer or changes during the writing stage) to see what else the story can do. What’s the (thematic) question that would run through the script? ‘Is he a good guy or bad guy?’ ‘Is he beyond redemption?’ ‘Can he have a normal life and family?’ Etc. Each one demands its own adjustments.