I'm not sure I even want more demos. In a way I'd rather they just work the full game to completion, I don't really want to have to keep replaying the early segments.
If we do get one more demo, it willl probably showcase the new battle system. But more than that I hope they showcase how the daily life aspect works, where you choose which areas to go to per day etc. We've had small, single-day tastes of it before, but I want to know what the average week or so will feel like. They can't write content for visiting the garden every single day, so I wonder how they will handle it?
In the next demo you'll be able to skip to where the last one ended. Of course, you won't have any stat points or +1s with people, but I'm pretty sure there's nothing in the next demo dependant on having a certain amount of points in a stat, at least not that I can think of.