What are winter classes like?

Hii! There’s a class for my major that I have to take in order to unlock all the other classes and there’s only one class for 120 students to which it fills up VERY fast… there’s only 31 spots left. Im a freshman and I want to get this class over with so that for sophomore year I can do the other classes so if all the spots got filled up for spring, I was thinking of just doing it over the winter. This class is fully online I just wanted to know what winter classes are like and if it’s worth it.