I run unofficial LineageOS 14+ (formerly Cyanogenmod) on my device, a Samsung Tab S 8.4 LTE.

I have searched many hours over many years through untold XDA forums in regards to Ubuntu Touch but with the latest Unity8 news, there might be more hope for modifying the kernel (like Linuxium does for Baytrail tablets) to run full fledged Ubuntu but alas I have never found it. Android just works too well for the demands involved in doing so.

Technically from what I have scoured, the biggest hurdle is related to what is described as the lack ability to do a mount loop. There are a few poorly recorded YouTube videos but with zero documentation, years old now.

I was extremely happy to see the Note 2 being listed on UBports as a potential device...but I don't think it suffers the same issue as the Tabs.