If it continues, you are probably looking at replacing the big (5" diameter) seal that goes around the hub drive. Not an overly hard job, but you do have to pull the pumpkin off to do it. Some have had success by running a piece of film or thin cardboard to clean the seals groove much like the forks can be done. I've never had that luck. Short term, just keep checking and adding fluid until you get home. Don't tighten that filler cap too much, it is cast aluminum and a few have broken theirs rather easily.
You may want to find a 5 minute car wash every so often if it is creeping onto the tread. That kind of oil will take you down in a heart beat.