I suggested some (possibly) ideal partners for this in a meeting once, they & others present didn't seem terribly interested at the time though.
I don't think they should do it entirely on their own, they should use a distro that's ideologically & logically very similar, & just get Sailfish & it working seamlessly together.
Get something going that's roughly akin to what Ubuntu's trying to do... Apologies if I don't respond to any responses, not sub'd to this thread.