Thank you for all your replies.
Unfortunately the Airbus 320 probably not as modern as your bombardier in terms of computing power ( always thought it was very backwards when you can't display constraints and airports at the same time on the ND). Would be handy having a temp compensated profile.
Yes I had considered increasing the platform alt to 3390ft and starting the final descent from the 8.8nm however my companies procedures don't mention this. I'm sure nearly a decade ago that our procedures did mention about increasing platform alt but this seems to have been taken out. I have certainly not discounted this method and as Skyjob mentions your platform will also be affected by cold temp so it seems to give you more safety margin relation to terrain to do this. Also I've noticed a lot of the VNAV approaches ( in normal temp conditions) we fly the FMGC seems to compute a 3 degree profile from a higher alt than the platform indicated on the chart. Some as much as 1300ft above platform and ATC have never questioned us yet so increasing platform for temp is not dissimilar.
FlightDetent. You bring up a very good point about keeping things simple for ATC. Could imagine a tricky situation especially for busy parallel approaches although saying that the chance of having to two non ILS approaches in a busy international airport at -20 would be practically zero. Also hadn't considered the FPV to be baro angle and increasing FPA. I'm sure we used to have a table for that but that's been removed ( not sure why).
I think the chances of it happening for real are pretty slim ( in the sim anything is possible) but if it did happen hopefully you would have enough time to plan for it. Initially looking at this scenario it looks relatively straight forward at first but actually going through the cold temperature tables and correcting each step down height without making any errors takes a fair bit of time and capacity. As Flightdetent says I certainly would not want to be doing this calculation on the approach. There is a handy quick to use App which calculates the profile temperature corrected however not sure I would be too confident whipping out my phone mid sim/ check flight without a raised eyebrow from the trainer.
I bring this scenario up as I've heard it been given in the sim where you are given a diversion with not much time to perform an LNAV approach needing temperature correction. I think certainly a few potential gotchas if not considered before hand.