Re: Why in the Star Trek universe are so many planets named with numbe
Andor: Paradigm was written and published long before ENT's Andor episode. But I don't know if we can definitively say that the Andor seen in ENT was actually a uniformly cold world; all we saw were its arctic wastelands, after all.
For whatever it's worth, though, the novel
The Chimes At Midnight establishes that the Andorians were undertaking a terraforming effort in the mid-23rd Century to, well, promote global warming.

Though
The Chimes At Midnight is a
Myriad Universes novel set in an alternate timeline where Spock died in childhood.
Now, I don't blame Jarman for the discrepancy there. Okay, I blame her
some--or, if not her, whoever solidified the concept of Andor in DS9R--as she or they chose to abandon the traditional fanon depictions of Andor. That's very little blame, of course, as no writer should ever be beholden to the irrational whims of the likes of us.
Nevertheless,
Enterprise did choose to draw on it, and if one goes by ENT, it's a bit of problem. Nothing insurmountable--I understand it's been surmounted nicely enough.
Still, it was a little jarring in
Paradigm when I was reading about some islands somewhere, and realized that this was, as they say, no moon.
It's not the freezing--someone with more knowledge of astronomy than I could better explain the climate and seasons of a Galilean satellite, although I expect the revolutions around the primary to be a very much greater influence on temperature and weather than the axial tilt that is the biggest cause of seasons on Earth.
Nope, it's gravity. Tides on any Galilean satellite would be grotesqueries of those we experience. Tides on Io rip the planet half the shreds, tides on Europa crack open a shell of ice up to two miles thick--tides on a temperate, Earthlike moon should be putting tsunamis on the beaches daily. I doubt anyone on Andor lives on any archipelago, or within a few miles of any shore. I doubt they could have colonized any other continents on their moon prior to the invention of lighter-than air vessels--I'm not sure they could have even finished building a boat.
Now of course if Andor is pretty much ice-head-to-toe, I guess tides would become less of a concern, but I doubt they could be totally dismissed for navigation. Alternatively, Andor's primary might be a smallish gas giant, with the less severe tidal forces that would entail.
Some more general, rambling thoughts:
It occurs to me that a sufficient concentration of sunlight should be be able to reach Andor, because we
do know there is photosynthetic life using water as an electron donor to replish the planetary oxygen. O2 doesn't stay molecular oxygen for long, and needs to be replished through a biological cycle. However, despite the lack of green life on the parts of Andor we've seen on the screen, there's still enough oxygen to support a human as well as an arbitrarily high number of aerobic Andorians. (Now, there are strong suggestions there isn't as much plant life, or as much oxygen, as there is on Earth. I would figure the blue respiratory pigment, presumably copper-based hemocyanin, of the dominant animal form on Andor and its relatives is life adapating to a thinner oxygen content than Earth-normal, though, like animal life did on Vulcan.)