Quote Originally Posted by Questioner View Post

My question to you: Can an entire book be one of the acts in a novel series, and contain multiple "smaller" acts? (What I mean is that the novel contains the different acts, just like any other would, but is still an Act 1 of the overall series).
Yes.

A Game of Thrones is a good example of that, in that it does set up a lot of the overarching conflicts for the series. But it's also a story in itself, with plenty of conflict and complications, whose resolution (I use the term advisedly) functions as the kick-off for the next volume.

A different kind of example would be The Lord of the Rings, which is one novel that was split by the publisher into three volumes.