Judy has a nice setup, but keep in mind that the accurite and thermostat temps might be off a few degrees. Personally, I would trust the thermostat temps on your Ranco.

Also, if you know the Accurite temps are pretty close to your Ranco, then your setup should work as well. Just bump the temps of the Ranco until the warm side is where you want it. Even if the Flexwatt is at 105, that's not too warm and your thermostat will protect it from overheating. I believe Flexwatt will max out at around 110F, but there is a possibility that it can go MUCH higher if it wasn't controlled by a thermostat or rheostat.