There's a pic of the Woodstock Cat thermometer in this post. Looks like a surface reader, not probe. If so, a standard Condar stove top thermometer will work.
Here’s my morning update. Fully loaded (to the max) at 8:30 pm, damper fully closed, cat engaged at 500 degrees, and left for the night. Now 7:30 am, pictures attached of stove temp and coals. Wondering if any other PH owners are seeing the same results with less wood? I’ll be testing more after the holiday weekend.