This is my first year with over wintering geese but I have duck's, chickens, Guineas that I have overwintered for 4 years. I have combined them all in the past to make it easier to feed and water but this year I will separate the ducks and geese they slosh the water so much it makes a big mess.
I feed oats early on and when above freezing and supplement with high protein feed or corn once a week. When it gets below freezing I cut the oats out and feed ground corn 18% hog feed far cheaper than poultry feed and will feed poultry feed at least couple days a month to make sure they are getting all needed nutrients