I have a hosta in a half barrel that is in the corner where the porch meets the house. It sits on the cement sidewalk. I have had a hosta in it for the last few years and it has done so well that I had to dig it out and split it last year. It also has a lady's mantle in there but I need to dig that out as it gets smothered by the hosta.
Hostas are very tough! I accidently left one in a bag (dug it up to bring home to plant and it got shuffled around and forgotten). I found it laying out by the tree this spring and it was growing in the bag--barely any soil--just what was on the roots when it got dug up.

It can but if in doubt, cover the insides of the barrel in styrofoam and top with mulch when the weather gets cold.

If you decide to go ahead with this, do NOT use anything but your choice of potting mix to fill the barrel. Anything you put on the bottom 'to improve drainage' will in fact hinder drainage by raising the perched water table in the planter and reducing the amount of space available to allow for a proper gas exchange/air for the roots, which will lead to small plants at best and root rot at worst. Your winter foe is not frost, it's freezing/thaw cycles and layering the top with a generous amount of mulch in the fall will help a great deal.

Pieter.....who grows almost all of his Hostas in pots

Great info! Tomorrow I'm going to put two new hostas in large pots!