Measuring engine temperature, No taco sender or gauge ... Options

[Chaznaster]

Hello all. With the weather getting warmer, I have started thinking about getting a handle on my engine temperature. I looked at quite a few discussions on here and most were about interpreting/ calibrating the stock(ish) gauges.

I have no sender at the taco plate and no gauge.

I happened on the approach to measure with a dipstick thermometer but it appears those are all NLA.

I have a 123 dizzy that transmits temperature but am pretty sure the base of that is far away from the sump and probably not an accurate reading.

A few questions:
* Is the 123 temperature value good for anything? Maybe there is a conversion? Although I expect it will warm slower and cool faster than the sump in the best case.
* What is the most straightforward way (I am OK with some spend and even running wires to the dash) to get a reliable reading? Gauge (VDO or other), thermal camera pointed at the oil pan? Other?

I appreciate your guidance ...