I would just unpot one and check out the roots and medium. If there are problems (and after only a year - there probably are not if your orchids are not showing signs of distress. If they are, the medium might not have been very fresh to begin with ) then repot all. If you don't see a problem, you have time. The seedlings (if still fragile) can be left longer if you don't see problems. Just remember as they grow, their roots will mingle making the a bit harder to separate - but not impossible. Good luck, Richard.