Personally I don't believe that it was a good idea at all to adapt this book to a movie. I've read the book and seen the show. The book was a reasonable read but really had to have the reader look deeply and imagine what the area and situation was like. Putting into a show is almost as if you are being told that "the story was like this" when there are so many other endless possibilities to what it could've been.
The storyline was also a bit dodgy. It talks about how Ann Burden thought she was "the only person left in the world" in the diary format. If you look carefully she talks about how the United States were bombed. It does not tell that any other place was affected by this Nuclear Holocast. And even if other places were bombed somebody had to bomb it, and they would still be alive and running.
When you put a book from a diary form into a show it really just doesn't work. You are no longer in the first person view, even if the show just used the storyline.
Also in the show Ann never talks about the Nuclear Holocast. In the book the words "Nuclear Holocase" are not once mentioned. The only reason why people assume it is a Nuclear Holocast is because of the book's blurb, which says she is the lone survivor from a Nuclear Holocast. While some may argue that she didn't write the blurb of the book, the whole storyline is all over the place.
You have to give credit to Robert o'Brien and his family for the fact that the book even got published though. O'Brien died before he finished the last chapter of the book and his family finished it for him, as well as have it published and so on. In a way you could say it is a tribute to him.
If you are looking to relieve boredom than I wouldn't put this down. However I do not think it is great and there are better one's out there, even on the same topic. Anything like "Tomorrow Before the War Began" by John Marsden would be similar but much more exciting and realistic.