First of all, I've never used this particular strain before, so take my advice with a grain of salt. The elevated temps for a saison are used to both increase yeast-derived flavors, and ensure high attenuation. If you want the higher temps to have the yeast give you more character, it needs to be early in the fermentation. Most of those flavors are created in the first few days. Slowly ramping temps up, or letting the yeast free rise over the course of the ferment also ensures that the yeast finishes, which is important with some of the more finicky saison strains, like Dupont.
Keep in mind that most saison strains still give you plenty of yeast character at lower temps, it's just going to be different than at higher temps. Experiment to see which you prefer. Lately I've been using the Wyeast French Saison, pitched in the upper 60's, and ramped up to the mid 70's over the course of 10 days or so, and have been very pleased.
In your case, I would suggest warming the beer up maybe 5 degrees since you now have the means, to see of the FG will get any lower. Don't be surprised if it's done though.