There are 4 of us, and I no longer buy onions or garlic or shallots. I plant about 4 or 5 bulbs worth of cloves in late November, then I plant shallots in Feb and onion in March. This year I planted 500g of shallots, and they and onions yield, for me anyway about a 1:6 ratio. I planted brown and red onions over about 12 sq m plot and I got about 15kg of onions. I feel like I use them a lot but maybe not. Remember that some inevitably get a bit damaged and have to be eaten more quickly.
I planted the same amount last year and I just finished as the new lot were harvested.
I do not do overwintering onions.