I've seen self-striping yarn that can sort of mimic Fair Isle, I've thought about trying it. The little I've done Fair Isle style didn't have as much stretch so I thought I'd try it and save FI for other things. If you find out there's a way to do it stretchier, please let us know!
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper