Note that the movies imply hours, but the actual travel times were not discussed. I genuinely prefer a galaxy of days travel to the minutes to hours of Disney Star Wars, but that also makes Luke's dagoba to Bespin survivable in a fighter (1d 3h vs 27 days)...
I'm aware of the charts. A chart isn't a system unless it covers every option. I have my own chart for like 120 star systems within a single sector. But there are 1000 sectors and something like 400,000 chartered inhabited systems and tens of thousands more operated by smugglers and squatters and illegal corporate operations without a charter. Granted, I doubt a map existed at the time they made the charts so any means of systemizing things would have been nigh impossible because at the time no one would be able to say how far apart any two systems were.
I also agree that travel times in days make more sense than travel times in hours for true galaxy traversing jumps (as opposed to jumps within sectors where I think hours are fine). And I think you are correct, 27 days in hyperspace is beyond the range of an X-Wing in just about every respect to say nothing of pilot comfort.
My system rates that a 4 sector outer rim jump between a charted world and a developing world, normally requiring 12 days even in a ship as fast as an X-Wing - still beyond an X-Wing's range. But.... Luke almost certainly wouldn't have plotted a direct jump between those two points, and if you do it right, you can cover Dagobah to Bespin in a hurry. First, Dagobah while almost never visited is actually on the Rimma Trade Route. So you can plot a jump from Dagobah to Eriadu on one of the fastest routes in the Galaxy. That jump only takes 24 hours by my rules. From Eriadu you can now jump on the Lipsec Run to Gerrenthum in the Javin Sector. That jump takes less than 2 days. Finally, there are local trade routes in the Javin sector, and if you look at it Bespin is on one. So Gerrenthum to Bespin is actually pretty darn fast. That jump probably takes no more than 5 or 6 hours. In total, Luke can make the trip in around 3 days. That's within the range of an X-Wing (even round trip!) and while Luke wouldn't have been comfortable, it's theoretically doable. It's also possible that Luke knew of local cells in the Sluis or Javin Sector where he could stop for a few hours to get resupplied and stretch his legs. More on that in a bit.
The real issue in the Lore is that both Hoth and Dagobah are on trade routes! They aren't really even obscure systems (like Yavin actually is). They are actually not only charted Republic worlds, but are potential stop points along trade routes. This makes them anything but secure hiding places. Like, the Empire easily has the resources to investigate Hoth without straining the fleet in any way. Hoth is even by the lore in a rather important trade sector. These are systems that existing resources would be used to monitor. Maybe Yoda easily hides from sensors, but an arriving fleet in the Hoth system probably doesn't. Part of the problem here is the Legends lore diverges over the question of whether or not you have to plot jumps on hyperspace routes or not. Some of the lore indicates that the only jumps you can make are jump point to jump point along standardized routes and that you can't just jump willy nilly between any two points but have to traverse in real space to particular points and then follow the routes like roads. But lots of lore seems to dispute this as well. I've resolved this by saying normally, most jumps are plotted very routinely to minimize the chance of accidents, but that you are free to take out your nav computer and plot as inefficient of jump as you like through rarely used hyperspace.
Another issue is that if Luke did in fact use the hyperspace routes, his jumps into important systems like Gerrenthum and Eriadu probably weren't without incident. Contrary to Andor season 2, you can't just jump an armed snub fighter with its transponder off into a major civilized system without coming under notice. Note that in season 1, we get a much better take on this with Andor using a common civilian craft without its transponder on and evading local interception on a somewhat backwards corporate world, until they check the logs and notice it. If you try doing this on Coruscant, Gerrenthum, or Eriadu, you will get noticed in a hurry, especially if scans determine you are a military vessel. So I would expect that the best possible flight path I outlined above would get hot in a hurry, especially since in the case of the outbound flight from Hoth to Gerrenthum, he'd have been jumping in a sector where the Imperial fleet had just engaged the rebellion and local customs and other naval assets would have been on high alert. There might be entire undocumented adventures in trying to save fuel and life support consumables to make a jump to Dagobah, or from Dagobah back to Bespin.
But then again, maybe Luke was high enough ranked (as Commander of Rogue Squadron) to have information about local rebel cells in this part of the galaxy, and could have availed himself of local infastructure by jumping to systems other than Gerranthum and Eriadu but which were still well suited (probably with secret Rebel route mapping or purchased from sympathetic smugglers) to utilizing the existing galactic hyper-routes, got himself a hot meal and a shower and refueling at some small hidden base, before continuing on. This would avoid multiple combat engagements and made the whole thing a lot less stressful.
UPDATE: The point of this discussion is to draw a sharp contrast between whether rules define narrative or narrative defines rules. Because I have a system narrative is forced out of it by the choices the rules force on to characters - including Luke Skywalker. It's easy to see why Lucas, adapting the real adventures of Luke Skywalker into a movie chose to leave out lesser incidents for the purpose of pacing. He was making drama, not a historical documentary. The fact that it took two weeks for the Death Star to go to Yavin from Alderaan, or that Luke potentially had encounters with the Empire on the way from Hoth or back to Bespin doesn't have to be spelled out in the movies.
