Often when a series dies a quick death, the story arc ends in an uncomfortable place, but it would appear the producers had advanced warning, because OUATIW ends neatly, in very much the way one would want it to.
I wouldn't say it was perfect in all ways. I felt there were some flaws in the logic here and there . Amara wound up seemingly less powerful than Jafar), but the story is wrapped up nicely. And while in previous episodes I've found the Red Queen's reformation a bit unpersuasive, at this point I'm used to it, so everything felt as it should.
The story was completed so neatly that I actually don't know how the creators had pictured it playing out if it was picked up. Would it have been this same story arc, stretched out for several seasons? Or was this going to end and be replaced with some new drama? I guess I'll never know, but the end result is a very satisfying miniseries.