Pots for Autoflowers

Hi I just planted 5 lowdown autoflowering seeds in red plastic cups. I was wondering what size pot to use next so that I only need to repot once. Right now I've got 5 gallon pots, wondering if thats too big?

I grow alot of autos, and i usually pot the seeds up in their final pots.
I use 1.5L or 2L pots, and they are more than ample for these lil plants..They shouldnt get root bound either.