Did the SPBMV & HMHV II (HIT Maintenance) plans followed by the Century plan earlier on this year for a few Audaxs I’d entered earlier this year. So I would give a thumbs up for your plan.
April 200km (10,000ft ascent)
May 400km (18,700ft ascent)
July 200km (12,000ft ascent)
The plans I did put me in good condition for the events, especially as I’d never cycled more than 70 miles in one ride before. The FTP improvements thread shows what plans I did.
Knowing you have the fitness goes a long way as when doing these events as I find its more of a mental challenge to complete.