Depends on "tiny" they got drainage holes? you'll see roots popping out... i don't like the tap root (or clones root) wrapping around a ton of times at bottom of container. Once i know it's a solid root system i can easily pull the plant out of container without hte soil disentegrating, it's time to transplant for me. 2-3 weeks? but if like a solo cup, closer to 10-14 days, probably.
you might want an intermediary pot size.. possibly 2 of them.
large pot, small plant has complications -- if familiar with that, ignore me of course. In most cases large portions of soil will dry out significantly while only watering around the plant as it grows into it. otherwise, fertilizing areas where roots do not exist only builds up dangerous levels of nutrients... hidden until the roots get there and then BAM! huge problems all over the plant.
it is doable... just becareful of buildup and try to hydrate edges occassionally without drowning plant. it'll repel water if it gets too dry and becomes very very difficult to saturate. doabel, but likely disrupt roots and such.