Would you use a internal hub for touring? On face value I wouldn't feel comfortable with that knowing a mechanical fault could mean the end of touring. Maybe a rohloff or more simple 3 speed hub but not sure. A derailleur setup seems safer or even single speed if going somewhere relatively flat.

There's a company near me that specialises in touring bikes and they seem very keen on the Rohloff hub. You get a choice basically of derailleur equipped or Rohloff bikes and no other options.

Thorn touring bikes and tandems

Saying that those are serious touring bikes that take serious weight and abuse.

I mean if you get a problem with a derailleur system you can often rig it as a single speed or get it back working to a degree but there is the possibility with internal geared hubs they will make the bike unusable. If the hub gearing breaks up inside, a part cracks etc you can't ride it.