I'll evaporate off 85-90% of that water.

I should be able to fit the frozen cubes into a large freezer bag. The fat will be separated, refined & stored in jars.

I don't drink the stock, I add it to soups & sauces. The insert for my ice-cream maker takes up more freezer room.

I have 2 X 300L freezers plus my fridge's freezer. I also have a big (30L) aluminium pressure cooker. I find the frozen cubes more convenient.