<human>: Posting here because there wasn't a more specific, active subreddit about roommates.  

I like my current place. My roommates are all good guys but we don't really see each other or even communicate beyond a whiteboard on the fridge. In the town I live (small college town) most people find a place to live for the next year around the end of the first semester. Potential roommates for the next year begin to decline exponentially after the first semester. If I want to stay here I need to start looking for roommates now. 

I wrote a note on the whiteboard asking everyone's plans for next year about a week ago and haven't gotten any response. I also talked to everyone in person. No one has solid plans. The lease is up next June. It's not unreasonable to ask what their plans are going to be 6 months down the road, is it?

I don't want to put myself in a situation where the current roommates can't stay at the end of the lease, and be on bad terms with them for the latter half of our current lease. 

At what point have I given ample time for them to figure things out?  
Should I start looking for potential roommates now?  
How do I broach the subject of "Hey you can't live here next year because you couldn't give me solid plans for next year?"

Can you summarize the given text in a few sentences?
<bot>: Current roommates are bojangling about plans for next year. At what point have I given enough time for them to figure it out?