Maintain Up-To-Date Copy of Very Large Table if Clustering/Partitioning/Moving Operation Needs to be Killed/Rollback
I've done this a few times. My servers are only 2008R2, however. I've moved tables like this and 'partitioned' data both because data files were reaching the max size (16tb) and identity columns were reaching the integer maximum. 

Index rebuilds on big tables can take some time to roll back. Reorganization does not, however it is much slower (single threaded). You can kill it immediately and it will just stop where it is, so you could maybe do it over the course of several nights if need be. I had to do this with some quite unwieldy full text catalogs. 

Rebuilding clustered indexes to new file groups is not an online operation if you have a (MAX) data type in your table -- see comments below. That was something that surprised me when I was working on my process. 
Also, be careful with sorting in tempdb. I once attempted a full statistics scan on a 3tb table and my 500gb tempdb LUN ran out of space overnight. 

Let me know if you have any questions. 

Thanks