Yep, I brew 5, 10, and 15 gallons. Just double and triple. I will say though use some common sense. I made a mistake of adding too much chocolate malt in a 15 gallon. The 5 called for 2oz (just for color really) so I figured for 15 I better just use close to a pound. My amber turned into a brown, still tasted great just one of those "not what I was going for" beers.
I've also found you can be a little more 'off' on hops and it doesn't matter as much. If the 60 minute is 6oz with a 15 gallon and you only have 5oz, it's fine.