Hi! I can't give an extremely reliable opinion on how long for your retake, since I started studying/ took mine 7 months after failing the first time. For me, I had roughly a month until my exam (21 days actually studying) with ~100 hours (I'm studying full-time). I definitely went overboard in comparison to what people usually say to spend on BEC, but I was stressed about failing again.
For me, I use only Roger. I personally remember things better when I write them, I usually write the book, cover to cover, paraphrasing/ using shorthand where I can, along with color-coding and bullet listing when possible. I skipped 70% of my lecture videos once I realized that I wasn't utilizing my limited time efficiently. My first attempt was very unorthodox, I spent only a week studying for my exam before I took it, and never did a single MCQ/ SIM/ WC, so I went into my exam pretty much blind.
For my second attempt, I knew what my weakest area of focus was (Operations Management, especially cost accounting), and spent 50 hours just on that. I started using the Cornell-Method for note taking. It's still time consuming, but I found it to be a little faster as well more efficient when it came to reviewing my notes. Once I reviewed/ wrote through all the sections, starting with the areas I believed to be most important. I also took the time to do MCQ the final week leading up to my exam (but only for I/C and Corporate Governance).
Considering what I would probably have done differently, as well as your situation, first figure out how you learn/ study best. If you can just watch lectures, or just MC, do that. I definitely found going through MCQ to be extremely helpful, and wish I had given myself more time to that for each section. Going through the MCQ, taking notes on what you did wrong and marking the topics/ subtopics you seem to be getting questions wrong on the most will help you I.D. your weakest areas. I would make sure to definitely know Corporate Governance (COSO, I/C) and IT a lot.
I also regretted not checking out WC examples, as I had spent too much time attempting to figure out how to structure and answer the questions. For SIMs, they provide ratios, but not for MCQ. However, knowing the main ratios/ concepts for Financial management and economics (Elasticity/ Nominal vs Real Interest Rates/Exchange Rates, ROI/RI/DOL, NPV/Payback Period/IRR/ARR and how they compare/ contrast, Probability Analysis/ Profitability Index, WACC/CAPM) should be enough to get you through. For operations management, main ideas/ calculations for Step allocation, Joint-Product Costing, Process Costing, LIFO/ FIFO, Variances are important I, believe.
If you can stay on top of it/ consistent I would say you can study and then take the exam in 2 weeks. Focus on your weaker areas, and then branch out. Do some SIMs/ and few WC. But for those I wouldn't spend a ton of time on, just on how to structure your answer, and know the overall purpose/ main ideas for the main topics (E-Commerce, IT, Disaster Recovery, Internal Controls, Corporate Gov, Variance Analysis, Flow of Costs/ Inventory Costing/ Management, Economic Indicators/ Markets & Efficiency)
Sorry that was a lot, but hope it helps!
AUD: 84 (4/18)
BEC: 88 (3/19)
FAR: 6/10
REG: 7/19