It depends what moves you want. Alola Vulpix is one of my favourite new additions. My current one is one that I bred to have Freeze Dry and Moonblast + Snow Warning ability. If you want one for Doubles, I think Blizzard + Dazzling Gleam is the better choice of moves and you can get those two no matter what level you choose to evolve it as you can just relearn them with a heart scale. Also don't forget that Blizzard is a TM anyway, so can teach it or remove it at any time for free.
I started this recently too, after finally finishing Final Fantasy XV, and I'm hoping to get through it before Switch arrives. It's my first of the 3D Pokemon games, my last one being Black & White (which I wasn't a fan of). I'm loving it so far. It's seriously good looking, the artistic design making up for the 3DS' limitations. I've just finished the first Island (what happened to Gyms ), but some of the changes are interesting. Am I right in thinking map obstacles will now be taken care of via Pokemon you ride and therefore you don't need to build a team around having Pokemon able to learn the TMs that can take care of such obstacles? That's a big step forward if that's the case. I'm not sure I like the wild Pokemon calling in friends though. Some of my battles last much longer now. But I'm very early into it, a lot can change. I genuinely can't get over how pretty it is.
I really need to get back to this once I'm done with Zelda, couldn't stop playing first few weeks but got busy in all the Christmas rush and haven't been back since. Probably around half-way through the main story at this point.