Supposedly WY3724/WLP565 (aka Dupont) is a wine yeast that evolved over time to work in a brewery application (Dupont's brewery).  This would explain why it can work at higher temps than most brewer's yeasts without producing fusel alcohols and excessive phenols/esters.  

With respect to it stalling, another characteristic of wine yeasts is that many of them do not work effectively under pressure.  Homebrewing setups, along with commercial brewhouses are set up to have the ferment pressurized (either from gas in the headspace in the case of homebrewing or from forced pressurization in some commercial brewhouses).  

The solution that I have heard to this (but not yet tried) is to use a piece of foil taped over the airlock bung instead of an airlock.  This will let out a lot more gas and not pressurize the fermentation.  I am dying to make a saison now with Dupont, because while there are other yeasts that can make a good saison, Dupont consistently will make a GREAT saison (if treated right!).  

It may be a little late to try it on this brew, but I would think the combination of warming, rousing, and depressurizing might get it moving again.  If that doesn't work, grow up a slug of brettanomyces and let that finish it off, and try this on the next beer.  Good luck.