Re: Amuse me, sailing small boat offshore.
"The Dove" movie was shot with a Ranger 23. "The Dove" book and true story were done with a Cal 24. The trip was finished on something larger, he didn't do the whole circumnavigation on a Cal 24.
I think the primary problems with increasing standing rigging size would be:
1) Drilling out chainplates to allow for larger clevis pins would weaken them.
2) You couldn't tension to the max safe limit for the new standing rigging, you'd probably want to stick with the max tension of the old. The chainplates and other parts of the rig probably wouldn't be designed for the higher tension.
There are a few 27' boats (Pearson Tritons and similar) at Shilshole marina with windvane steering systems. An easy one to find photos of is "Darwind" aka "The Pink Boat" which is setting off for an around the world trip soon. Some have outboards. It should be possible fabricate or model one for a smaller boat. The Triton only has 4" more beam than your Ranger, and the transom may actually be narrower, but it doesn't share the transom hung rudder.
I think you could find a boat that has proven around the world trips, like the Pearson Triton or Albin Vega, for not much more than you can sell the Ranger 23 for. The extra 4' of length would provide a lot more storage room for essentials like water. It would also have much better carrying capacity.
1986 Pearson 28-2 "Elena"