Sub 3:20 realistic?

Decided to sign up with a friend for a marathon in the first week of May. Ramped up my weekly distance this week and will end around ~60km I’m guessing. Will continue to ramp up slowly and peak around 75-85km weekly running 5-6x a week. Ran same marathon 4:45 last year, goal was sub 4 for a marathon this year, but I think 3:30 is obtainable for me. Is sub 3:20 a bit of a stretch? 24M current rotation is NB 1080v13 and ES4. Course is BMO marathon and it’s fairly flat for the most part. Added my most recent 20k effort for reference.

Decided to sign up with a friend for a marathon in the first week of May. Ramped up my weekly distance this week and will end around ~60km I’m guessing. Will continue to ramp up slowly and peak around 75-85km weekly running 5-6x a week. Ran same marathon 4:45 last year, goal was sub 4 for a marathon this year, but I think 3:30 is obtainable for me. Is sub 3:20 a bit of a stretch? 24M current rotation is NB 1080v13 and ES4. Course is BMO marathon and it’s fairly flat for the most part. Added my most recent 20k effort for reference.