I would just mash at a higher temperature. I don't think you'll get very close to the beer if you don't use a Saison yeast. You can make a good beer without a Saison yeast, don't get me wrong, but it will be different than Tank 7. Also I have a hard time believing the FG given. Especially for the Brett version, there's just no way that a Brett version is going to stop at 1.020. I haven't had this beer for a year or so, but it is not at 1.020. That much sweetness would be very noticeable in a Saison.
I'd just use your 3711 and let it do it's thing. Stop it when it's under 1.010 or wherever you'd like it to finish by cold crashing it.