Tote your wine in a green bag
It's pretty user-friendly, though I wish the handles were longer so I could carry it on my shoulder. And if it were truly a green bag, it would be made out of hemp, jute or cotton rather than polyester (though I know those aren't as easy to wipe clean.)
You can buy the E-bottle wine bag at DC area wine events and festivals, or on Winemania's website. They are $13, or 2 for $21.