well, they probly ok for a few days/week...you want them to develop a good strong root system before you re-pot, but on the other side of the coin, you dont want to get too many roots and crowd them, so if you look at the height, width and overall "mass" of the seedling to imagine how developed the roots are, it should give you an idea.

ive done a quick picture of a seedling that needs to be re-potted to give you a guideline....you can re-pot before, but but the roots are small so care must be taken when disturbing the soil.

hope thats of some help