I think that's a real good question and I won't pretend to know the answer. From reading a bit about the problem I found a chart that showed the decrease in the life of an LED driver when used in higher temp environments .
So I would guess that the driver will work OK in the hot attics but will not last as long and I think you will have to de-rate current output for the driver depending on just how hot you expect it to get.
The main problem with "high temp" are the aluminum electrolytic capacitors used in the driver, they're mostly rated 1000 hours @ 105°C
I'll try to calculate the life expectancy of the caps:
I did a little further research. Apparently attics can reach 160F in Arizona.
160°F = 71.11°C, to simplify the math, lets say 70°C, heat from other (active) components and the caps themselves (from ESR and leakage) add maybe 10°C to the caps.
Life expectancy of the caps are: 1000h * (2^ ((105 - (70 + 10)) / 10)) = 5657 hours.
After 5657 hours of operation, the electrolytic caps capacitance would decrease by about 30%, how would that affect the driver depends on the driver design.