Is it just the one evening you are away? Will you be there the following morning? If so I would think, if she totally refuses the bottle, to maybe offer her a yoghurt or cheese or other snack, pancakes or toast maybe, and a drink of water. I would imagine it would be fine for one night and she'll make up for it the next morning when you bf. She isn't going to let herself starve, although I understand your concern.
Maybe it's time to switch one milk feed for a snack with a drink of water?