Hello Pete, I would consider to buy a cheap "chinese power meter" with some attenuators and/or a directional coupler.
If you have a small dummyload that coupler is not necessary but is maybe very practical for future in-line measurements.
See other topic "chinese power meter".
I bought one and (if calibrated for 1 frequency like 2400 MHz) it is a very useful meter. As i see that you don't have possibilities to calibrate it you can still use it with for example a 50 dB sma attenuator in series.
In that case you cannot tell the exact amount of power but at least you can see if power goes out!
I saw the meter for 40 euro at Passion radio in France so no need to wait till the Corona virus in China is gone.