The difference is notable in really cold weather, but mostly in usage. What it does (range mode) is not heat the pack above absolute crucial need and it limits the cabin heater power draw. The upside is that your power usage is quite decent even in cold weather driving and in most cases the HVAC works fine enough that it's not really an issue, but that is not always the case. Now the downside is that if you start the car cold you'll be limited on power and regen for quite a while. Due to no pack heating the regen limiter disappears REALLY SLOWLY. It may take hundred or more km to get fully rid of it if it's cold outside. While with the standard mode you're likely to have a cozy pack after 20-30km already after which usage normalizes, however those 20-30km don't be surprised to see 50-100% more usage due to pack heating.
And now I seriously doubt it degrades the battery as the pack is still maintained by the car, just not excessively. So if it's -20C outside it'll not try to get the pack to +15C, but more keep it above -10C or so, that's quite a large difference in power consumption (disclaimer: no actual facts on the temperatures, but that's about what I've surmised from hundreds of forum posts over the years).
