Yes it is. I know people who studied the book only 2 weeks before the test and they were fine. Now it depends on how confident you are. You can study 10 books for 2 years before the test but if you are not confident with no experience of taking tests or exams, you may make mistakes. But again 98% of the reports from test takers says the test was easy and it's useless studying days and nights.
The guide is the best, and only official resource out there.
More than studying, see this as an opportunity to get to know in a little more depth the country you have the privilege of becoming a citizen of.
I have read the guide three times, and each time I saw the history of Canada through different lenses. We are lucky!
Good luck!