Winter use: In Hawaii, that's not a concern. I am able to garden year around. That's one of the reasons I opted to move to Hawaii. So rather than talk about storing find for winter, I mention storing excess seasonal foods.
While I can grow many things year around, there are some crops that are strictly seasonal, while others tend to produce better some times of the year and poorly the rest of the time. Just like in most areas of the mainland, cool season crops do better during the winter months here, things like broccoli, cabbage, cauliflower. So yes, there are foods I tend to store, but not in excess. We are more apt to simply eat seasonally.
Some crops are strictly seasonal. They're mostly fruits. Seasonal foods that I preserve:
... Pineapples. I save this by either drying or freezing.
... Lilikoi. I juice them, then freeze the juice.
... Avocado. I'll mash a few and mix the mash with lime juice, then store in the freezer. Once thawed, it's good for making guacamole, which hubby enjoys. I'll also use it as an addition to soups or as a "gravy" in stir fries.
... Mango. I scoop the flesh into nuggets then freeze it.
... Turmeric. Dehydrate then freeze for long term storage. I could just freeze it, but it works better for my uses to dehydrate it first.
... Citrus except lime. I'll juice the fruits and save a few containers of each kind of juice. Limes produce year around, so no need to store extra.
... Jaboticaba. I'll make this into a syrup and freeze it.
... Coffee. I'll process the beans to the parchment stage then store them in my barn until roasting time.
Excess also can be preserved but I don't fill my freezer with too much excess.
... Bananas. I'll freeze a few dozen to carry me over until the next bunch is ready. Bananas seems to one of those crops where you either have none, or so many that you give them away.
... Assorted veggies. I'll normally pop a few broccoli heads, cut up cauliflower, carrots, and peas into the freezer. Not much. Just enough to add easy variety to our meals.
... Bulb onions. I have green onions year around, but I also grow plenty of bulb onions because we use a lot of them. Bulb onions all mature in the summer, so I end up with a seasonal excess. I usually just coarsely chop them up and pop them into the freezer for adding to soups later on.
Of these excesses, I prefer to use most of them for trading or selling.
Let's talk about emergency foods for a moment. I do keep a bit of food stored for an emergency. Emergencies I can think of would include a major hurricane, volcanic eruption, or a shipping disruption (strike, war, port damage, etc). Regardless of the emergency, we'd need food. We do have plenty of food growing about the farm, but it wouldn't take long to become insanely bored eating bananas, pipinolas, sweet potato greens, and eggs for every meal. So I keep an assortment of things growing around the farm, and I keep an assortment of veggies and fruits in the freezer. Not a freezer full, but enough for a couple weeks. I also have dry beans, lentils, rice, and peas stored in sealed mason jars for soup making. And a few pounds of spaghetti and jars of homemade spaghetti sauce stored as well, just for quick & easy meals. We have livestock living right on the farm, so if push came to shove, they could be added to the dinner plate. Unlike people living in urban areas, we live amid a trove of food. It's one of the benefits of having one's own homestead farm.