I'd have thought that would be enough to wash every 2 days, apart from the night nappies
- they'd be my worry as they can be very slow-drying (mine usually take 2 days even with a brief tumble
). I'd throw in an extra night nappy just in case (also, just in case there's an unforeseen late poo!), and probably go heavy on pockets/AI2s with quick-drying inserts (even hemp should dry in a day as long as it's the sort of insert you can unfold), and just bring a couple of super-absorbent fitteds for if you need them to last a good while.
If you're going to wash every day though, I'd say maybe 12 day nappies (including some that you know will dry super quickly) and 4 night?