FWIW You can leave beer in the secondary for years if you have a high ABV. Hoppy beers I would not suggest long secondaries... maybe a few months at most. Strong malty beers may require some aging in the bottle/keg/secondary. Your oktoberfest may benefit if it's a high ABV brew.
Relax, don't worry etc. and so on.
Primaries: Old Ale, Barleywine, ESB, Scottish 80/.
Secondaries: Lime Wine, Strawberry-Banana Mead, Carmenere (from 144 lbs of grapes!), Engl. Barleywine, Modded JOAM, Concord Grape Pyment.
Kegs: Choc/Coffee Stout, Saison, Dry Stout.
Bottles: Belgian Str. Dark, Dubbel, Cider X 2, Modded JOAM, RJS Pinot Noir, RJS Aussie Cab. Sauv.
Coming soon: Blueberry Mead.