I could honestly see Nami's dream happening during a time skip or epilogue sort of thing. Same for Chopper perhaps. Not that I want that, but their dreams seem to be the most time-extensive. I also feel like Oda lowkey just spit in the face of Chopper's dreams by having Law's DF be a thing, but oh well lol, he'll find a way.
Nami's is only time extensive if she does it by boat. I fully expect Franky to make Sunny an airship that will allow them to travel anywhere they want with ease. There's also the weapons to consider. If one is a giant mermaid one of them at has to be in the sky too. Nami has lots of options here. She could make her world map from above.
And clearly, the SH's are going to fight the WG in a massive war after finding One Piece and Luffy might destroy Reverie (if Dragon doesn't first). I have never in my wildest dreams imagined ending right with them finding One Piece. It's been built up for a long time that government doesn't want pirates to even know what it is, hinting they know what it is and don't like it. It's also hinted One Piece might be related to the void century. Luffy will topple the WG and destroy FI during this war probably.
Further more, it'd be easier to get back to Laboon by airship as well. Being able to fly around the world would be a unique thing in the world of One Piece beyond a bird DF and would be the definition of freedom that Luffy craves. No way is Nami charting the world map just by boat and going to every island by sea.
As for Chopper it always made sense to me that Luffy would get an incurable disease in the New World and they'd travel to find a cure. They could very well use the search for a cure to explore the world by air right then, in fact.
