I do my bulk aging in Corny kegs that I use for beer.
They are stainless steel and can be sealed tightly.

I purge the keg with CO2, then rack the wine.

After I rack the wine I then purge the head space with more CO2
It is then sealed tight.

Since these kegs are tall and skinny, I can store more of them in my
fridge for cold aging.

I own close to 30 of these kegs.... cost between $10 and $20 depending
on the source.