I DID NOT give myself enough time to study for the DAT (about a month), and got a 20 in the biology section. I wasted a lot of time reading through/taking notes on cliffs & feralis notes, and it's just not an effective way to actually learn and remember information. It's really easy to accidentally spend a lot of time reading stuff you already know and skimming the stuff you don't, because it's more comfortable.
If you need the refresher, start by skimming through feralis notes (I'd mostly ignore cliffs because they're just a redundant, less thorough version of feralis). But focus MOST of your time and energy on just running through the practice tests on DAT bootcamp. Most importantly, read through the explanations of at least the questions you got wrong!! Then, if you notice you're missing a lot of questions on, for example, taxonomy, THEN crack open your PDFs (& google as needed) to understand taxonomy better.
TLDR: Don't focus on memorizing 29 entire resources (B/C feralis has everything you need) as much as on figuring out which topics you need to review.