Good question.
I use a 5 gallon bucket and it all goes into my garage fridge.
Two methods to measure.
Method 1: put the bird in the bucket/tub while the bird is still in the package. Fill up the bucket/tub with 64oz pitchers of water and count how many you use. Fill until you are about 3.5 inches over because the cavity of the bird will take up water when not in the packaging. See how much you have written down and you can use new water if needed or just stick with the water you used already. If using that water then take the pitcher and pull out 64 oz of it so you can blender up the salt, sugar, and cure in that water :D
Method 2: (my preferred method) Put the bird in the bucket WITHOUT it being in the wrapping and start filling up with a 64oz pitcher. Go until barely not covering. Then take your number and add 1 gallon to it (two 64oz pitchers) and you can use that last 1 gallon to blend up your salt, sugar, and cure and pour it in to finally cover the bird.
My mother likes to buy smaller turkeys like 10-12 pounds and use a big roasting pan to do this.
If you spatch cock or half the bird you can also easily use a meat tote/lug, or big roasting pan to do this as well. These are wider than taller and may help with people's fridge dimensions.
My garage fridge stays pretty empty in the fridge section so I can do things like this.
Only the door and the freezer part have things in it.
I hope this makes sense and ask all the questions you have :D
