Maybe its a good idea to create a module to be able to drive remotely from the webpage and send messages or graphics to the Arduino if something happens. Like a certain temperature is reached , or you just want to send text to the device from the dashboard or even have a duplicate graph of the temperature on the device itself.
The best and simplest OLED SSD1306 is the I2C version in my opinion.
like the ones here: https://plus.google.com/103070915152061549912/posts/6A5D19QYb4f
or this : https://plus.google.com/103070915152061549912/posts/59roGku6HAa
With Arduino you can code all of this locally. You could even set up virtual pins to click a button in Cayenne and have it determine what it needs to do on the Arduino display. I don’t have and OLED displays but i have code for some 16x2 LCD displays. If you want to see it let me know.