Fantastic list
@nicholb. I drove last winter in Alberta with a 3 LR RWD. Many trips to the ski hills. Long road trips in -30C. Drove through the worst 2 blizzards in Alberta last winter. Lots of experience here!
Chill mode and low regen. Tesla recommends you put the car in chill mode and low regen for slippery conditions. I did try that last year and quickly went back to normal settings. For one, in cold weather you already have reduced regen so setting it to low did nothing much. As for chill mode, I find I can easily modulate my acceleration for the conditions and don't really need the car restricting me. If you are having trouble, you may want to give those a try for yourself.
I had no use for Chill mode last winter. Simply feather the accelerator properly. In extremely icy conditions (think freezing rain with a dusting of snow on top) when the regeneration is mostly back (battery fully warmed up), you might want to reduce the regeneration in settings to avoid a nasty surprise. It happened to me once, but traction control quickly kicked in and nothing happened other than a 1/2 second butt cheek clench. The rest of the time standard regeneration was fine.
Defrost. The front window defrost has two settings. On the first press the icon turn blue and it directs cabin temperature air to the front window. On the second press the icon turns red and it directs full heat to the front window. I wish there was something in between. During snow storms the first setting is not enough to keep the window clean and the second setting is like having a hair dryer pointed at your face. Turning up the cabin temp does help the first setting.
If the blue/red settings aren't working for you, go into the climate settings for the car. Manually set the temperature and fan speed and where to direct the air (you can pick any one of/combo of defrost, vent and feet). That's how you can get "something in between".
Wipers: If you're worried about the wipers freezing to the windshield, then turn on Settings | Service | Wiper Service Mode. This will move the wipers up a couple of inches. They can't be lifted off the windshield and stay there, but it does make it easier to lift the wipers off the windshield if needed when you get back. I suppose you could place an object under them if really needed.
Slip Start: Settings | Driving | Slip Start. If the car is on ice it's possible to press the accelerator and nothing happens. The traction control system (TCS) detects that the wheels will slip and in order to prevent slippage, no power is transferred to the wheels. Flip this setting on and the TCS will allow some slippage to let you get moving.
Keep Climate On: Whenever you run into a store and want to come back to a warm car, remember to press the Climate control button, then turn on Keep Climate On. Guilt free toasty cabin when you return!
Supercharging: I had real issues with very slow Supercharging due to a cold battery. This was an issue even after 4 hours of highway driving in cold temps. I really look forward to seeing how the battery pre-heating works this winter. I spent a couple of long calls with Tesla support while having issues with this and I suggested they implement a fix where if a Supercharger was a destination in the Nav, then they pre-heat the battery. I was thrilled to see this implemented. Now to see how it works in a Northern Canadian winter!
Tires: The Nokian Hakkapeliitta R3 tires were fantastic and confidence inspiring.