Dave, I won't tell you that we can go 15 days on the black!
Takes some practice tho! We can go longer on the gray as well, but ya gotta take showers in the bathhouse, or in this case, in your friends house. If we do that, we can take 60 gallons of fresh and 15 days on black and gray and galley. It is a challenge, but we have done many times.
Sounds like you are enjoying your new baby!
Carol