Picard, at some point, says the Federation is 8000LY in diameter with 150 inhabited worlds. This means the density of inhabited planets is well below that of an average of 10LY between each planet.This is Star Trek, you can't go to a system without tripping over, not only habitable planets, but ones that have intelligent life, and pressures and atmospheres exactly like Earth. And really. They don't actually need a habitable planet. They just need somewhere do dump everyone until they can move them somewhere better. With replicators it shouldn't be a problem to give everybody a pressure suit and set up a bunch of air refill stations and whatever sort of future space tents they would need.
There may well be other planets that could theoretically support life. However, assuming the relocation of 10+ billion people, how do you propose they dump them on a planet with no infrastructure to keep them alive when they are there? Food, energy, other resources. Even replicators can't make something out of nothing. They'd need a second huge armada just to provide for them. A planet that were not habitable would be even worse, because they'd also need life-support domes.
All that chart tells you is that the canon warp speeds from episodes are completely meaningless because they are utterly inconsistent. I mean, there's another "canon" report of warp 9 in that chart that's half the speed of the one you cited.And you can do math all you like, but it's a canon fact that warp 9 can do 10 light years in 51 hours.
One could argue that warp speed is just a "base" that is modified by other factors (gravity wells, space dust, etc.), either way there's no particular reason to think that a round trip to other useful planets is shorter than the scale of days-weeks.