Idling (or "excessive idling" which is really the problem, not idling in the normal course of stop-and-go traffic or startup) is going to have a much greater effect on the wear components of the engine itself, regardless of the oil used, and relatively little effect on the oil itself, assuming a reasonable Oil Change Interval (OCI).
Not sure about the diesel idling thing; having worked in the far north where no diesel motor is shut down 24/7 unless it has heated indoor storage (and there isn't enough of that to go around) so spending 12 hours idling overnight is a normal operating condition unless operated over two 12-hour shifts. Same with half to one ton pickups ... nobody shuts them down and they are inevitably diesels, no gas motor light trucks.
Reason is simple, if you shut it down, two hours later (can be less, if wind cools the vehicle) it will never start with out aids (running a flex pipe from the exhaust of another running diesel to the engine compartment, then covering with a tarp for an hour or so is the usual method). Boost (or "Jump") starting isn't going to be enough by itself on a cold motor. Yes, it's cold, below -45F, I've seen it at -52F.
In any case, many of these trucks and heavy equipment run long hours or miles, as good as any warm-weather example. I see no evidence there is a detriment to the additional idling.