The story focuses more on the girls and Olaf. Story is great. It was a bit short (only 90 mins). Lots of funny moments, emotional moments, dark truths. Overall it gives a good message. Trailers and the numerous possible plots were slightly misleading. I'd say you should go watch it.
Movie duration should have been 120 mins. That's my only complaint.
The movie is complete with post credits scene and everything and it's like a perfect ending with less chance of a sequel yet if Disney wants, they can opt for a sequel(not necessary).
That being said, I loved the movie. 90 magical minutes of my life. I will watch it again.