We have on occasion brought something to drink. Recently SWMBO bought us two flasks that are similar to a Platypus. I put rye whiskey in mine, and she put rum in hers to mix with some sort of powdered drink mix that she said wasn't so good.

I brew beer and am near to trying my hand at mead and wine, and bought some plastic bottles meant for Mr Beer just for this or the lake.

We've also bought some cheap Merlot that comes in a container kind of like a kid's drink box that was ok. Much better than a glass bottle!