Keith, I agree with your assessment of the current crop of IR films, that said the OP has 1 roll of Kodak High Speed IR film and my exposure regime at or around 38º latitude does work remarkably well.
Hopefully this information may enable the owner of that roll to get a reasonably good strike rate.
We'll see, it could be off, as I well know.
Just one more thing to mention to the OP, load the Kodak film in total darkness, and I mean total darkness, otherwise your film will probably suffer from piping.
Piping is where light travels up the film via the leader sticking outside the cassette, it is a real and definite problem.