I simply won't buy it until there's a Linux version. It's pretty much my rule for games these days...if I have to reboot to play, I know I'll almost never play, so I just don't buy Windows-only games.
I only switched to Civ V from IV because it has a Linux version (and Civ IV does not, though it does run reasonably well under Wine, though I hate the fiddling required to keep Wine and GPu drivers happy through OS upgrades and such). Civ V runs as well under Linux as it does under Windows; not perfect, mind you, but it's not perfect under Windows either.
I wonder if it will be able to cope with case-sensitive filesystems? I still haven't got to play one on my Mac because they've never supported case-sensitivity.
I created a separate case insensitive partition on my MBP to deal with that issue. For things that really, really wanted to use the main partition, I moved their content to it and created a symbolic link for things like ~/Library/Steam that points to the other partition. Was a very effective solution.
Playing Civ 5 here on Antergos, works flawlessly, very nice experience. Having the successor for Linux as well would be just awesome. However, it's not totally clear whether it will be ported… cf. https://www.reddit.com/r/linux_gaming/comments/55vuci/civili...
I prefer playing on Windows, not only because of the sheer availability of games (and hardware drivers) but also because I don't want to have any chance of mixing work and play. I like to keep them completely separate.
I only switched to Civ V from IV because it has a Linux version (and Civ IV does not, though it does run reasonably well under Wine, though I hate the fiddling required to keep Wine and GPu drivers happy through OS upgrades and such). Civ V runs as well under Linux as it does under Windows; not perfect, mind you, but it's not perfect under Windows either.