Read the book. It's much better, and you have the time.
Read the book as King originally intended it.
When it was first published, his editors looked at it, said "You're a new author, and this book is going to be hugely expensive because it's so long. Cut 500 pages."
He did, and the story suffered, but it was still a huge hit.
Some years later he went back to his publisher and said "I want to publish the Stand was it was intended." And his publisher balked again, but by this time King was a massive cash cow for Doubleday and they relented, which is good, because the uncut version became a best seller again.
The miniseries was... a miniseries. Sort of like the original It miniseries. Good cast, but WAY WAY WAY too much subject material to be cogently plugged into such a short period of time allocated by the producers.