Things are definitely different nowadays, then they were 10 years ago when I was still around, so I can't say this for today. All this depends on way too much testing of weird combinations, and since I don't do this anymore, I don't have exact data anymore. But back in my days, there was no single race, where I wouldn't be using fluoros. At least as part of combo. Nowadays, Swix have Cera F powders which work extremely good with temperatures around -20c. I had beer or two with Swix tech in Val Gardena this year, just on evening before race, and he still had 2 pairs of skis to prepare for early morning, pre-race tests, so I went down to wax room first. All 4 pairs (2 already done, and 2 he did at that time) which were ready for next morning tests (for teams to get info about Swix waxes for race), were prepared with fluoro powders, so obviously things are still same. Especially considering temperature for all trainings and both races (SG and DH) this year in Val Gardena was somewhere between -17 and -25c, with extremely dry and cold snow.
But as I wrote, with such conditions, you need a whole lot of tests to get right wax. So for someone who doesn't have time (and money), and most important, a whole lot of experiences, most likely non-fluoro way would be better way to go. Especially, since in such conditions logical, one or two wax mix will most likely never work. My favorite combinations for such conditions were so weird, that noone even believed they would work, yet they worked better then anything else :)