Totally agree with @Miss Lydia I keep free choice main diet feed (flock raiser) and give corn as a treat during the winter every day. Summer I only offer flock raiser, We have 5 acres and a pond so they get plenty to eat. They rarely visit the feeders in the warm months.
I really don't mind my water fowl or chickens adding some weight during fall and winter they need the extra just as other animals forage to gain weight for cold months, once spring comes we take them off the corn and they will get into their breeding weight and with more moving around they will be in tip top shape. Just make sure they always have plenty of water available when eating just like normal. Yes your right now we want them to be able to fight the cold and stay healthy.
I usually do the corn later in the evening before they coop for the night. Severe temps I do a morning and evening feeding, about half a cup per goose. Mine don't over eat, and I just adjust according to leftovers.