I'm really looking forward to getting Torna. Interesting interview with (I think) Nintendo Life, in which Tetsuya Takahashi commented on the prequel being content that would have taken place between chapters 7 and 8 - and he's also said he thinks Torna is best played between chapters 7 and 8 of the main game.
I got a little fatigued with Xenoblade 2, due to some of the baffling design choices others (and myself) have mentioned throughout this thread. That being said, New Game Plus does appeal now some of the rough edges have been honed off. I'm considering getting Torna as a physical release, downloading the expansion pass content so I can unlock the DLC Blades in my current save-file, then starting a New Game Plus. I'd do up to chapter 7, then play Torna, then do the final chapters - and this time I'd aim to recruit all the rare Blades and do all the side-quests.
I really don't know if that's compatible with real-life, though! Maybe I'll just do Torna for now.