Too Much Too Young!

Need some advice regarding my present grow which is in a wardrobe and therefore of limited size. I have 5 seedlings on the go at present and the time has now come for the final repot into 15 litre containers. Hower I will only have room for 2, maybe 3 pots under the light so I was wondering how I can get round this. once the transfer is achieved I estimate that they will need another 2-3 weeks of vegging, then possibly another fortnight of flowering before i can determine their sex. At that point i would like to be able to replace any males with one of the remaining pair of "indeterminate" seedlings. I therefore need to know if it's possible to keep these seedlings viable & small until I ascertain the gender of my "big" plants. I'm assuming that if I repot these and leave them in daylight they will continue to veg & grow, meaning that after 5 weeks of hanging around they will be too big/stretched to fit into the wardrobe. Would keeping them in 4 inch pots and giving them minimal nutes help to keep them tiny and useable? Someone suggested giving them only 6 hours of light per day would arrest development but I'm hoping someone has successfully dealt with this dilemma before. Any advice would be helpful- last time I was faced with this problem I bit the bullet and threw the unused plants away. BIG mistake as (yes, you've guessed it) my preferred pair were blokes:mad:

I'd say get some outside. They don't need to go into large containers yet, so veg them for as long as you can, then put some of them outside to flower. That's what I'd do.