It's possible the PSA BEVs heat the battery pack in cold weather.
E.g VW ID.3 does this, if the battery is <13C I think, and it takes a chunk of energy to do this! Had an ID.3 briefly, and a short trip of a mile to shops & back last winter would see me getting around 2 to 2.5 miles/kWh! I didn't keep this car very long, lots of things I didn't like about it & I much preferred the Ioniq 38 I was planning to sell on. The same trip, same temps, in Ioniq would see me getting my usual 4.7 m/kWh. Big difference is the Hyundai/Kias don't bother preheating the battery at start of a cold trip. Maybe that's worse for the battery, who knows? But I'm generally driving around using 20-30 kW power, and the motor's rated 100 kW, so I don't think the battery gets stressed by my gentle driving. I believe VW have had a lot of complaints about this power-hogging, and something's getting changed in the s'ware to fix/ameliorate this issue.
All I can say about your figures is that the figures you're seeing are atrocious. My GOM in cold weather with 100% SOC and 38.4 kWh usable (probably 41 or 42-ish total?) will show me 170 mile range. And if I drive around a bit, the range drops in line with the miles I've done. I simply do not see sudden losses of 20 miles, and I don't see why you should either.
Ioniq 28 & 38 are the most efficient BEVs around, along with Model 3. Looks like PSA have a lot of catching up to do!