We no longer buy 2l bottles of any kind of fizzy pop on a regular basis - only when expecting lots of visitors or events like Christmas. Instead we buy a tray of 330ml cans for regular drinking, and the baby mixer cans for mixing (cos I usually only have 1, if having 2, will go a large can!!).

Tis slightly more expensive, but we don't drink a huge amount of fizz, and it means we have nicely fizzy fizz when we want it, fits in the fridge well so it's cold on demand, but a half full and flat bottle is not clogging the door for weeks on end (and the toddler is less likely to ask for it as often if she only sees cans the odd time rather than the bottle every time the door opens).