I haven't been getting concerned about it, considering I have only so far driven the car at 10C (50F) ambient temps or less. It is also tricky to figure out what the true oil temp is from the gauge with only a few lines.
But, if you go to this site
911 Gauge module overlays that supplies numbered module overlays for the oil temp gauge and I take the B overlay and put it over the B gauge (which is the one I have), I would have to say that my typical max reading would correspond to about 180F, which is about halfway between the base and the first mark on my gauge. Assuming that my thermostat is functioning properly and opening at 184F, than this would suggest that everything is working as it is supposed to. That sometimes (probably correlated to lower ambient temps) the car isn't getting to 180F and when it does, the cooling system is not being over taxed and is keeping oil temp at the 180F level. As we get into spring/summer and ambient temps increase, I will be curious to see if this changes