The general training plan should look like below. Remember its a very difficult ride. Early start gives you the best chance of acing it. Join our whatsapp group if you have any questions for me. You could also comment below.
October - Do a super long ride. 600 - 1000k. This would serve a couple of purposes. Ensure a preferred starting slot and get some miles (albeit junk) in your legs. Also start paying attention to nutrition. Upset stomach is a major showstopper in ultra events.
November - Get the routine going. Fitness should approach 50 by now. Follow your training plan. It would be a good time to be done with a 600k of the qualifier SR. as weather is good
December - Ideally do an ultra in cold night conditions. This will help you settle your winter gear and give you some much needed cold night riding experience.
January - Now its time for muscle building. Need to constantly up the FTP from here onwards month on month basis. Regular training, Fitness 60+ is the expectation. Try to get done with the SR. No more brevets outside the compulsory SR needed.
February - Fitness 70. Time to lock your bike fit. Take expert help if needed. The goal is there should be no change in bike fit from here on. That includes saddle. New saddle is not a good idea going forward.
March - Fitness 75. Training hours would be a lot by now. Upward of 400k a week. Start locking in your bike packing. Next 4 months should be spent working on the FTP. Spend time with weights. Lots of climbing. Stick to a polarized plan. Avoid junk miles of any kind.
April - Fitness 85
May - Fitness 90
June - Fitness 100
July - Fitness 100 till middle of the month and then we start a slow taper.