If I have to add oil hopefully its not a full quart so buying it on the road isn't a good option for me. I carry a partial bottle in the upright position in one of those nifty zippered pouches that the dealer sells. I've had to add oil on the road but it's only been several hundred cc's to bring the level from near the bottom to nearer the top of the window. Necessary or not, that's how I do it. Anyway, never had a problem with the oil container leaking in the pouch.
2011 BMW R1200GS
2012 BMW R1200RT