[aerohead]

I went online and looked around.
One site mentioned that mineral oils were okay to 250-300-degrees F,while synthetics could see 450-700 degrees F without catastrophe.
Some members are wrapping their exhaust to limit exposure along with heat-shields.
Up to the limits,the hotter the lubes the better for economy.Furnace Creek,Death Valley,California temps would be okay for all oils on a daily basis unless under extreme service.
Low drag achieved through streamlining would lower the road load of the vehicle,and with it,the friction-heating effects of power transmission viscous shearing.So extra heat would actually be welcome.
You might fully warm the vehicle and do a temp survey with I.R. pyrometer,then cobble a low-cost pan together and compare the effects.
In a worst-case scenario,just compromise the pan a bit to allow some strategic airflow,or do some dedicated NACA submerged inlets with ducting to critical areas with outlets, as done in some high end supercars and racing vehicles.