For travel I bring a Platypus. They have a
wine version that holds 800ml. You just squeeze the remaining air out and screw on the cap. I've kept wine successfully for a week (haven't tried longer). The best part is that the Platy folds flat and weighs almost next to nothing. I bring at least 2 (one for white and another for red).
They are BPA-free and don't leave a plastic-y aftertaste. If I'm going winery hopping, then I bring more