interior probe placement I'd recommend with a glass tank in a regular room. The glass is a great insulator so the temp under it will not correlate to the temp inside well. It will take vigilant monitoring to keep the temps from changing. i disagree that the snake could move a well attached probe. The accounts I have read about probes being pulled all mostly come from exterior mounting and being pulled by kids dogs and doors being the most recent. My opinion do what you feel is best. I have removed a few UTH and have a 50% success rate I'd have a spare handy in case.

I also recommend a fail safe thermostat in case.