homemade tortillas for a crowd?

I'm attending a Mexican food themed BBQ in two weeks and I am considering making flour tortillas for the masses (50+). I believe this is no small feat, but I have a reputation to uphold.

I've only made them small scale before for instant consumption and have come up empty googling. Any ideas? This is complicated by its location in the forest preserves. And please don't bother posting any recipe that doesn't include lard .

-ramon