You could try killing Penumbra with Poison Cloud, or by tossing poison bottles at her feet. That might prevent the cut scene and let you enter the room. Otherwise, Telekinesis would allow you to grab anything of value within range (don't recall there being much there, though).
You could teleport in, but loading the game would likely trigger the cut scene right away. Maybe teleporting in without talking to the bartender would help.
Teleporting Anywhere, via hex editor