Would think that it all depends upon what steel you're using, and more importantly, how much you're using it. You should be able to plan most of your usage in hours before re-sharpening is going to be needed.
One of the small pocket "stones" in a case makes a lot of sense to me, if some touching up is going to be required. Then again, given your age, I assume you're going camping in the family rig. Probably plenty or room for the 204.
I'm real fond of the Gatco TriSeps. About 4" long ceramic stick, with an end that enables using appropriate angles, and will handle many serrations to boot. Plus fishhooks. I've never played darts on a camping trip, but they're covered too.