I don't use any bentonite, or other clarity agents in my meads. I move them as needed, to another vessel, before they go to bottle. I prefer at least 10 months (12+ being preferred) in bulk/batch form for anything 14% or under. Anything in the 14-16% range will generally get at least a year, maybe 14 months (depends). 16-18% goes 13-18 months before bottle. Above 18% I plan on at least 18-24 months before it goes to bottle. I'm a patient man when it comes to my meads (my beers too, but those are often done in short time frames). I still have some bottles of what I made in 2010, so I'm good. I'll be bottling a 14% maple mead/wine either this month, or early next (started early December 2011). I have a 21% that I started the same week that I need to start the flavor additions on. I plan on going at least another 6-12 months before that's ready for bottles. I also started a 16% mead in October that I plan to bottle after a year (or so). I'm getting ready to start a batch that should go to 18% within the next few days. I'm also looking at making another maple mead/wine this month, that could go to 18% (not sure which yeast I'll use, yet) or above.
IMO/IME, time is your best ally when it comes to making mead. Proper formulation, treating the yeast right, and moving it ONLY when needed is also important. I have the meads that are done fermenting in the basement (around 56F) just waiting for me to bottle them. Just need to get the bottles ready and do it.