Not sure where you are from there, but, if we are talking 4.5 to 5 litres ive got an experimental temporary storage idea on the go, im stacking mine in the bottom of my wardrobe as im stuck for storage space, demijohns and carboys don't really fit the bill for me, because you basically cant stack them, so, ive come up with this idea of stacking containers, using plastic stackable containers, which should be good for a few months provided you don't leave loads of air in them and bottle after 3 months or so, or at least move them on to a better long term storage idea, for me it has filled my gap for temporary short term (up to 3 months storage)
Im from the uk and got these are food grade containers for a pound each, they hold 5 litres, are flexible so don't crack, are clear so u can see whats going on inside them are easily cleaned for reuseage and are also stackable, both in and out of usage, which means they are very easily stored within a limited space.
For me that has sorted my temporary storage problems, while I can age stuff at least a few months and carry on fermenting within a limited space.
Ive added a photo that demonstrates the stack ability and how they stack wen not in use.
The stacked ones are filled with water merely to demonstrate weigh bearing ability and the ability to stack and lock with the lid below.
Maximum capacity is around 12 gallons, which for the bottom of a wardrobe isn't bad imho.
At a push it could go 14 if u stacked the fermenting vessels on top of maturing ones, but, that is pushing the space to the maximum and u would need sufficient space to store what u wanted to age elsewhere.