After reading some of the novel chapters. I noticed that there are a total of 25 chapters in Volume 1 (SAO). With 5 or so side-stories that the Anime already used like the murder-case epsiodes. Chapter 1-3 was basically Episode 1. And since there are 25 episodes total. They will definitely fit everything in Volume 1 in, despite them already leaving a few minor parts out that make you question things. So if anything, since so far there have been no filler-like moments. It's definitely going to go with a cliffhanger like Volume 1 did to lead to ALfheim Online.
I wouldn't click around anywhere else beyond that link, unless you're okay with spoilers.