Is moldy leaves a problem on overwintering plants?

Four of my five brussels sprouts plants have leaves with big black spots all over them now. Half of my eleven kohlrabis do, too. I guess I shouldn’t have been surprised. We’ve had lots of rain and well-above-freezing temperatures for the past two weeks.

Are they done for? Or is there a good chance they’ll recover just fine when the spring comes and they have more warmth to regrow?