What are some good foods for the winter?

Here are a few more options:

• If there's a nearby pig village, give four monster meat to a pig, then kill the resulting werepig. This yields two meat and one pigskin. It's the same amount of total hunger (50) you'd get from turning the monster meat into eggs, but you can dry the meat on racks and get 20 health and 15 sanity in addition to the 25 hunger per jerky.

  If you have 12 monster meat, through this method it becomes 6 meat, which equals 150 hunger, which is 2 days' worth. You can use this to calculate how often you'll have to trek to the pig village.

  Plus if the pig village is far away, you can use the pigskins to build pig houses closer to your base. (But not too close or you might get swarmed by werepigs during full moons.)

• You can hunt for koalefants. Killing one gets you eight meat and one koalefant trunk. Assuming you cook the trunk, that's a total of 275 hunger, which is 3 2/3 days' worth. Have a boomerang handy so you can goad the koalefant to attack instead of running away.

• If you're near a swamp, you can look for merms killed by tentacles. Each merm drops one fish and one frog leg, which nets you 25 hunger, so 3 dead merms will feed you for a day, and you can dry the fish and frog legs. You're also likely to find more monster meat from spiders in the swamp. (Just watch out for tentacles.)

• Killing a tallbird and stealing its egg gets you 2 meat plus the tallbird egg, for 87.5 hunger (if the egg is cooked). That's 1 1/6 days of hunger from one tallbird + egg.

• If you're near a sinkhole, you can watch for batilisks at dusk. They frequently drop batilisk wings, which when cooked get you 18.75 hunger, same as monster meat, but with +8 health and no sanity penalty. They also occasionally drop monster meat. So 4 cooked batilisk wings yield 75 hunger (1 day) plus 32 health.

• One of the easiest ways is spiders. They give plenty of MM to eat, glands for health and spiderweb for sanity (hat or tent). Don't forget you can also catch spiders using traps.

• It was implied before, but a birdcage is a lifesaver. Cook the monster meat and turn it into eggs. Two eggs, a morsel and one meat give bacon & eggs, one of the food that stays fresh the longest. Great for a longer trek, or to survive winter.

• Get morsels by killing rabbits and birds. A boomerang or traps are the easiest options. Watch your naughtiness!

• It's winter! Hunt McTusk and his son, they drop some meat too. Not enough to survive on, but their other loot (hat, tooth) is even more valuable.

• A default option, but use your stockpiles from autumn/summer (the easy season) to eat in winter.

Honey is great for winter. Convert all your meat to jerky which has a very long spoil time compared to meat, and will take twice as long to spoil in winter. I assume you have an icebox, which would be a good place to store all your spoiling items. Stock up on berries, carrots to make better meals in the crockpot.
If you have the time, catch rabbits and store them in chests. They can be stored indefinitely and can be killed for fresh meat if you are in an emergency. However, each rabbit takes up one slot.
It is always a great idea to set up various farms in summer for your winter survival. (Bee boxes, rabbit farms, etc.)