Nissan US supply oil coolers (at a quite a price) but I have read that owners have then had issues with getting the oil temp up to anything near working temperature when not on track or during cold weather
So far I have not seen anything above 94 and that included some 'spirited' driving in Wales - and it mostly hovers around 88-90. So unless some serious track work is envisaged or climate change means we get US temperatures, I don't see it being an issue here, but that does not mean I will not be keeping an eye on the oil temp guage.
In fact, as the digital light system for water temperature is less informative than the guage in the 350 I will be regularly checking what the oil temp is doing, particuarly in warmer weather.