We mostly camp in Provincial, State or National campgrounds even when touring. Your site might not have a sewer hookup but they often have a dump station for registered campers to use.
Win - the 59G plumbing diagrams for the 2014's & 2015's show both sinks drains into grey tank. PDF:
http://www.winnebagoind.com/diagram/201 ... _plumb.pdf Is it different on your new 59G compared to the previous one?
The bathroom sink in the 59K looks like it drains into the black tank. (Confirmed for 59K:
http://www.classbforum.com/phpBB2/vi...=24059&#p24059
I had a Class C in which the bathroom sink drained into the black tank.
Re: dump stations - I'd say not overly difficult to find a place to dump. RV dump stations is one of the categories in the RV GPS we have but I have not had to use that category.