An extract from our ops (company) manual -
VNAV approaches are based on the use of barometric vertical path computations and as a result subject to the effect of temperature deviation from the standard. Under extreme cold temperature conditions (ISA-45deg), the vertical path angle can decrease by as much as 0.5 deg. Applying a correction to FAF crossing altitude will not correct this problem. Hence it may not be possible to use VNAV under extreme temperature conditions.
So the FD mode of the VNAV cannot be utilized to try to achieve a FMC computed/guided vertical descent to an LNAV minima (below ISA-45 atleast). Might as well use VS FPA to LNAV minima
Between the lowest temp limit published on the chart (when the design procedure becomes 2D)
to ISA-45 (different for diff carriers I am assuming), probably use FD (VNAV) with cold altitude corrections and ensuring all true altitudes are at or above the min altitude restrictions from IAF to touchdown.
That's my understanding after reading the above post for uncompensated BARO FMC systems.