Another option is to carry straight gauge spokes longer than you need. When you need to replace a spoke, take out your multi-tool (you do have one, don't you?) finesse the old spoke out, cut the replacement spoke down to size leaving just enough to put a 'z' bend at the end. Replace the old spoke with your new custom cut spoke and ride on. I used this method both on my own bike, and helping others out. I know from experience that the replacement spokes on my wheel (both drive, and non drive side) lasted for years through loaded touring, commuting, and just plain riding.

Long story short, the spoked wheel is a rather strong device. As long as you have something to take the load, you'll probably be fine.

Another upside to this approach is not having to carry spokes sized to your drive, non drive, and front wheel spoke size. And while you probably won't tie anything off with the extra, you could use the spoke to cook a hot dog if the need arises.

Have a great time on your tour!