It was probably some combined wisdom from folks here but if you are in the middle of nowhere you are probably screwed and will have to order from the interwebs or have it sent by a friend.

However getting a hand built wheel would be a good place to start. Someone like Bill Mould or Peter White would be great options for wheel builders as they both have a ton of experience and know-how to get something built up right for tours like yours. Bring tubes and patch kits and maybe save power food wrappers or dollar bills to use as tire boots and have two spare tires in your bags as well as some spokes and maybe a fiberfix spoke.

The most important thing that probably most anyone here would say is make sure your bike is in top working order. Everything is properly tuned and replaced and tested before you leave. What that would entail is tuning up the bike, replacing wear items (save stuff that isn't totally worn and use it when you get back), riding them for a little bit to make sure things are ok and then getting one final tune if needed. Make sure whatever backups or spares you have are new and unused so you can rely on them. Old patched tubes you have laying about and dried out glue won't inspire confidence. Just make sure the plastic cap is on the end so it won't poke holes in your new tube.

While on the road especially for your tires is keep them properly inflated and maybe check every so often for pokey stuff. Look over the rest of the bike as well and if you see something that looks like it is going wrong try and fix it if you can or seek help before the problem gets worse and derails your tour down behind the smallest chainring.

However Co-Motions are pretty dang nice so... ; )