The Crossing (2000) on Netflix

It's December of 1776. The American army under George Washington is a mere fragment of what it was in the summer, what with defeat after defeat at British hands, plus desertions and lack of supplies; and many troops had only enlisted until the year's end. The army escapes into Pennsylvania by seizing the only boats available, but the British will surely follow and wipe them out once the Delaware River freezes over. But then it turns out that the British are still in New York, Trenton (New Jersey) being held only by a smaller force of Hessian mercenaries. They're still tough, but maybe a Christmas attack across the river will catch them off-guard...