I did this last year using Wyeast 1007 German Ale. It worked out really well, and I'm planning to use it again this year. The major drawback is the beer won't clarify like a good oktoberfest should, but this yeast is a really nice alternative if you don't have lagering capabilities. It's a clean fermenting yeast that works really well for this style.
JRBrewer on Untappd
Planned - Saison (split batch with brett)
Fermenting - American Cream Ale, Darker Graf
Bottled - Purple Haze Clone, 7C's IPA, Cherry Cyser, Oktoberfest Ale, Cherry Cider, Belgian Strong Ale, Pumpkin Stout, Wheat Graf, Wee Heavy, Mead (split batch), ESB