Not really a wine drinker, so haven't had that much at once. Looking it up, half a 750ml bottle is about 5 units, which tells me that I'd be comfortable with that amount. When I drink, I aim to have enough to feel good, but to stop before I feel bad. If I have the spins, I've had too much. 8-9 units (so almost a whole bottle of wine) seems to be the sweet spot for me.