Q:

Tempdb approaching disk max: Is it OK to wait? 

Today my tempdb pushed up to the edge of the disk allocated.  Currently, said disk only has 10 MB left.  I'm pretty sure some bad reports run by a colleague earlier in the day pushed up the tempdb to this size. 
However, now I've got a tempdb size of 20932 MB and a space available of 20373 MB.  So it seems like we've got plenty of space in there to work with.  I'd rather wait until the weekend to do a restart and bring it back to a more reasonable size.  Am I OK to let this ride, as long as something unusual doesn't happen again? 
Working with SQL Server 2012 here.  Thanks. 

A:

This isn't a big deal -- in fact, it's the way a lot of people handle tempdb in the first place:

Add multiple data files
Pre-size files equally to nearly fill tempdb drive 
Set autogrowth to a small increment

If the space you have in there is empty and caused by a rogue report, I wouldn't worry about it, period. 
(This does assume you've set up tempdb on a drive by itself, as is generally recommended.  If you have other things on the drive that may require the space, you have to decide if there's a risk, and how to handle it).