Last year I brewed my O-fest on Aug 23, and served it at a party on Oct 22. 10 gallons, pitched 4 packs SafLager W-34/70 at 43 deg, let rise to 49 deg for 2 week ferment, then D-rest followed by ~4 wks lagering at 34 deg. Kegged & force carb'd.
It came out beautifully clean. IMHO it was plenty of time to turn it around.