TPMS - At what Temperature do I worry?

On my fiver I have four tires, so all I am concerned about is that the pressure is in the happy range, and that the tire temperature is about the same on all tires. Of course the tires on the sunny side will always read a little higher, but you get the drift. I have gone many a year without a TPMS as they werent available but now that I have had one I would never think about going without. Yes I know many say, but I always check my pressures. I don't doubt that, but all it takes is to pick up something from the road in a tire and it doesnt mean squat that you always checked as you are in for a hard time. Thats my take on it, so take it for what its worth. BTW one tire and rim will cost you way more than the TPMS and then if you don't catch it right away ythe damage to the unit can easily go into the thousands.