Yes, my listening room is hard to heat adequately. I'm aware that playing a few tracks is said to warm up the cartridge suspension somewhat, but I still wonder if it could do with some help as initially it can sound a little edgy. I do suspect that cantilever suspension temperature can have a significant effect on cartridge performance, and this isn't foo, it's an expected behaviour of flexible materials, even in space engineering, sadly. I agree that LED probably isn't much use whereas a traditional tungsten bulb a few inches from the headshell produces a noticeable warming effect.
When you consider how much fuss goes into phono-stage loading, VTA, effective mass et cetera, warming a cartridge to a suitable temperature seems like an obvious step.
These kinds of inconsistensies may be a contribution to the wildly different opinions we read of different cartridges' performance.