Is there an “Over-flowing Cup” in D&D?

I am running a game in which there is a player character that is basically a functioning alcoholic. I have made a special rule that requires them to be above a certain level of inebriated to function normally, and if they fall below that level, they get withdrawals, hangovers, etc; which affects their ability to function normally.

For the most part, this is working well. It makes for interesting gameplay, however there has been a few situations where the player has left the party to go “refill”, by simply hanging out in the bar for a few hours, while the rest of the party continue whatever they are doing. This has led to the player missing out on a few interesting situations.

This is where I came up with an idea – give the player a flask (or something similar) that can be filled with a liquid of their choice, that either

  1. Holds a large amount of fluid (enough to last a long time)
  2. Never empties

This way the player has to go for fewer “pit-stops” to refill their tankard.

Is there any items like this in D&D? And if so, how rare are they?

(For the record, I am using the 5e system, but if this item exists within other editions I’m open to it).